Look, I could make a long reply detailing the flaws in many of these arguments. I could point out that the issue boils down to the idea of a 'critical path' and optional sidequests which exist in most crpgs. Some games handle this better than others, but the tension is always there. Even the Witcher 3 had this dissonance. I could point out there is in fact a story reason to explore, which is Gale's quest for artefacts.
Of course you should be 'punished' for only following the critical path. If that were not the case the inverse would not be true, ie you would not be rewarded for dealing with the optional quests, which is utterly ridiculous.
Furthermore it is obvious, as many people have pointed out, that the game is laying clues for your motivations as a character to develop throughout the act. The why becomes as important as the how in other words.
This game is based on choices. You can choose to beeline to the githyanki (which will be mechanically hard I grant) or you can choose to listen to your gut if you pass the insight check which lets you know Laezal's holding something back from you. Hell, you can choose to kill her if you really want. I've seen the Ethel quest referred to a sidequest, but in fact you can learn a very crucial piece of information if you choose to let her help you. One that stands to the why AND the how. Shame it is gated behind certain choices and a literally crippling penalty.
If a dm had the nerve to tell me how I choose to make my character act according to his motivations is "bad roleplay", I'd walk out of the session never to return. Times a hundred for my character in a choice based crpg. Feel free to rp your own character the way you want and let me do likewise. I personally feel that treating a story as a desperate race against time without considering common issues like pacing, balancing quiet moments with tense ones, is a one trick pony, one that would become tiring very very quickly. But that is just my opinion.
I won't even ask people to stop suggesting that the game should be tailored to fit their narrow interpretation of the narrative and motivations. The reason being the game is highly unlikely to include any such suggestion and, after all, everyone is entitled to an opinion, no matter how badly thought out or applicable to only a few people.
But what is NOT an opinion is that there are other people who find a motivation to explore the story as presented without this suggested haste. They're not doing it "wrong", just differently.
