I think that the hireling system, as it is now, is intentionally kept to be unappealing, so that people will not use it. I remember starting my own first playthrough in the beginning of august and thinking I would use the hireling system, but quickly realized that actually Shadowheart, Wyll, Karlach, and maybe even Gale, was not such bad companions, because of how extremely poorly done the hireling system was. And so I went with the origin characters instead and didn't use hirelings. This was how Larian wanted me to play the game at that time. And I am actually happy that I did.
And I think there is a pretty good reason for this. Having played around with creating my own custom party via the multiplayer workaround and mods, and reading other peoples experiences in multiplayer mode, you quickly realize that this is simply not a part of the game that has been fully developed yet. The game is optimized for 1 Tav as it is right now, and that is the most immersive and full-fledged way to play it in the current version. There are so many bugs and issues with having 4 Tav's running around and talking to people and doing stuff on their own, the game is simply not able to recognize them as individual characters and it is a very messy experience.
Having said that, it is of course something that is being developed on, and I base this on two facts: there IS a multiplayer option and there IS a huge desire for customizable companions in the community. And if we know Larian, then of course they are going to develop this, but they are also not going to put it out there before it is optimized. It has not, understandably, been a top priority for them until now with the vast amount of bug fixes and work being done to prepare the game for other playforms than PC. But I would not be surpised if one of the next patches will adress exactly this problem: fixing the multiplayer experience and at the same time adding customizable companions - as I see it, those two are interconnected.
