If everyone made games based solely on what would sell - all we'd ever see is countless clones of GTA, Halo, and Call of Duty (oh, wait...
) If it's just about money, then why bother trying to make a quality game? If the majority of the market isn't interested in RPG mechanics, then why not just make a game about making a bunch of boobs bounce across the screen with realistic physics, in a post-apocalyptic world?
At some point you have to find a middle ground between "let's focus solely on making a good game," and "let's make a game that will sell lots of copies," or you just end up with stagnation. That's what Fallout 3 is supposedly trying to do anyway(if you look at all the GTA clones that came out after GTA 3 that tried to cash in on the "contreversy" market - you need to actually have a quality game on top of killing hokers and swearing.) All I would ask is that they slide the bar a little bit over to the side of gameplay. F3 is actually frustratingly close to doing so to begin with.
Presumably, it wouldn't even take up that much resources to do so (or make it any harder to play or make a viable character, either.) It's much longer, time consuming, and costly to go through the development process of adding a new weapon than the coding involved in making that weapon "work." All I'd be asking for is some more programming to add some more implementation and consequences to the Attributes, even out the levelling, and raise skill levels to 200 or 300. (Or to just throw out the current system and come up with something that works better - if you're just going to make something that plays like System Shock with dialogue trees anyways - why even bother with Attributes and anything more than a skilled tier system? Wouldn't make a worse game, necessarily, and it would be more appropriate for that gameplay.)
That's just programming, though - balancing would take longer than actually coding it in. And most of that's already been done - the beauty of already having two games before this one to see what works and what needs tweaking. It's not like you're designing a whole new system from scratch, after all.