Yes, min-maxing IS a reality in cRPGs. Even on good ol' P&P games you'd at least try to agree with the other players on a balanced team before undertaking the DM campaign. Or you could go YOLO but just meet your end at the hands of some low level monster somewhere in the beginning, which is part of the game, sure, but not very productive.
Well, apples and oranges. PnP is a "true" MP approach, while CRPGs in SP are completely different imo. There is a huge difference between interacting with real people and with pre-written AI companions. PnP and co-op are pretty much based on the interaction itself. It's the core of the experience and there is a completely different approach to gameplay requirements. Min-max in PnP/Co-op is based and dependent on the interaction with other players. Nothing of that is true for SP. In SP you basically just have to make it up with yourself, which opens completely different approaches to both narrative and gameplay decisions. You can easily scrap min-max approaches for a preferred narrative experience because there is nobody you have to justify for that, for example. It's true that many people in SP follow min-max strategies as well (and many of those who do actually come from PnP...) but it's neither a requirement nor does it have any benefit of its own. You don't help your party with it (like you would in co-op/PnP), you basically only make the rest of the game easier for yourself (while, weirdly enough, an overal easier gameplay experience is just one mouse click away...). So balancing a party in a SP CRPG or min-maxing your char is in no way a requirement. It's an option, another level of freedom, that you can value against other elements (like taking your fav companions with you). Myself, I often ended with taking the same companions with me in Mass Effect, for example, even though I knew that the gameplay would be a lot harder with them in my party. But I valued having them with me higher than having a balanced party. That was a conscious decision of mine, which is pretty much at the core of what SP RPRs are all about in the end imo.
It's not a mystery now that I can't care enough for handcrafted companions unless they really are tied to the main plot. I can't care less if they react to what I do or what I don't as long as I'll see them as simple placeholders, nothing more than some more stats for my character with a side-quest to go with. I have to admit I liked Liara+Garus in my ME playthrough, but really all they contributed to the game was a little quote here and there. It could have been anybody with me, it wouldn't have make a difference.
Honestly, I think we are of such fundamentally different opinion here it's pretty much impossible to find common ground. I care for handcrafted companions if they are well written. That's pretty much it. If they have a certain take in the main story only the better, but it's not a requirement. Well handmade companions always improve the emotional impact of any narrative in a party CRPG for me. They are basically what a party CRPG is all about for me.
So well, let's just take the companions that actually bring something gameplay wise if they have nothing to contribute storywise. Which isn't very different from getting a blank slate party right from the start. Hell, I can even relate more to Sir Pimpalot, the Rose Mage, as I created him with a backstory of mine, than to Grakkarian the Red Mage of the Fiery Hells, who I just tell to shut up everytime he addresses me because he annoys me but I still need my mage in the party. And it can be worse : if there is a risk he would want to leave because I constantly shut him up, I'd have to pretend I care just because I need my Mage. There would be a strong dissonance here between what I want and what I need, because, in the end, I have to beat the game.
Well, there is nothing wrong with having annoying people in your party in the first place imo. I don't get why some people mistake well written characters with likeable characters. I can enjoy a companion that is "problematic" if it's well established. I guess it's my love for well written characters and stories in general, which is the prime reason why I love story- and character-driven games in the first place.
On top of that your second argument has no big weight in DOS since you could already reskill your companions in DOS. So if you hate mage X that much that you can't have him in your party anymore, just reskill your rogue to be a mage and your good. DOS gives you actually that much gameplay freedom that you can even get around narrative "issues".
As a completionist I tend to do every sidequest, so it's not really that I don't like sidequests. It's more that, as I mentionned, I don't see a real difference between the random NPC that will ask for your help and a companion, except that I need the companion to be able to beat the game ( unless I mastered the game and am able to beat it with one char, which IS a fun challenge too ). This is very diminutive of the companions, but still a reality in most of the cRPGs I played. DA:O is one of the titles that come to mind where they actually succeeded in getting some of the companions to be important characters in the main story - namely Allistair and Morrigan. They had a real part to play. BG was about the Son of Bhaal and His Inferior Friends.
Sorry, but every companion in BG2 had a ton more depth than anybody in DA:O, no matter if they were part of the main story or not. Also, you can't see a difference between a random NPC asking for your help and a well established CHARACTER? Wow, that's pretty much denying that there is character writing in general if it's not intended to be part of the main narrative completely. I think that this is totally not true. BG2 for example had a shitload of extensive dialogues with your companions (between various group members, between them and the PC and a ton of ambient dialogue as well) that gave them a lot of depth as characters. Comparing that to a random NPC is completely pointless, even if you think that the companions have too little meaning for the main narative.
As I said, I trust DOS2 should be able to bridge that gap. Heck, I don't even really consider the 3 other party members to be "companions" but rather "full fledged main protagonists" in their own rights. I don't see them as another Khalid, Garrus, Leliana, or even Adora. This is all thanks to the concept of the origins stories.
I think this approach is designed to fail tbh. It's something that might work well in co-op (for which it is designed) and miserably fail in SP if it will stay that way. There are various reasons for that, starting from typcial player psychology to design obstacles to be honest. I'm pretty sure Larian themselves have not a single clue how to really pull that off in SP at this point in development...
And all this comes by no mean against the vision of DOS2. After all, it tries to emulate a P&P session where every player will not only have the interests of the group at heart but also his owns. And when those players will make their characters they probably will discuss who will hold which role in the group. Hence, balancing the party beforehand. This can translate very well and easily to SP.
No, it can't. Simply because PnP and SP RPGs are fundamentally different in a lot of core aspects of how and why you do certain things in the game. You might want to play a SP RPG just as an imaginary round of PnP but that's actually not how others envision SP RPGs to work at all. They (like me) see it as an interactive version of the traditional choices novel.