Well, I think people who start with the assumptions that streamlined = less complex, less strategic, or less thoughtful, are always going to under-appreciate the inherent complexity of streamlined games; it's more subtle, i.e. not flashing in your face, and unfortunately it seems that you need obvious "markers of complexity" to convince some people that a game is complex. It's saddening, tbh.
It's true that keyboards have more buttons than gamepads, but I don't think fitting what one wants on a lesser number of keys means that a game is less complex. The basic idea of any game is to define a range of actions which you can perform to do X, and the challenge is to use what's given to navigate the environment to whatever end.
That's why, I don't think complaints about being able to perform less actions are meaningful- first, it depends on the action you want to perform instead of what's available, and secondly, you have to consider the impact that including such action would have on game balance. More often than not, less is more.
But all of that is a separate discussion from being able to bind keys, which is a useful functionality, I agree- every game should let you do that, and even if it doesn't makes sense because people are going to complain about "consolization" if you don't. As long as it's easy to do, and not error prone, it should be fine.
Though really, TW2 is an action-rpg, so as far ARPGs go, it's fine with having streamlined controls.
As to a game not being "well optimized", well it sucks to have to accept it, but some games are just not going to work on less powerful machines because they require more labour; unless there's some marvel of engineering which will allow otherwise, the hardware of PCs are their limiting factors.
I do agree that it's more fun in an RPG, or action-adv game etc., when there are options for complex dialogue, complex NPC behaviour etc. For your specific example, though, the DLCs for Fallout NV certainly checked that box. I don't like it either that it took them till the DLC to make it better, but the fact is that they did, and I can appreciate that.
Also, contrary to what people will have you believe, PC gaming is actually booming. It's understandable if you have your preferences, but I just don't think more = better in all cases.