EDIT: just marginally related, but it's also part of the reason I've always been very dismissive of people who cry that "armor restrictions by class isn't realistic".
Yeah, you know what's the downside of removing the restriction for "realism"? That if you don't have any sort of class restriction (OR strong downside to use a certain type of armor over the other according to your role) you get and "end game" where your entire party is dressed with the same heavy armor... Because there's no reason not to, if that's the best available, and it's boring as hell.
I'm reminded of when I got to a similar point playing vanilla Oblivion: looting expensive ebony armour from every two-bit bandit to sell at a loss to merchants to accumulate gold to spend on... what? I already had several sets of daedric armour and the best weapons that money couldn't even buy and eventually found myself thinking "what's the point?"
At which point I loaded up a bunch of overhaul mods which nicely unbalanced everything meaning that I'd usually find rubbish bottom-of-the-range armour and other junk that could only be sold for pennies, which means that getting anything decent was either sheer luck (which was quite rare) or I really had to work at it. Suddenly it felt more worthwhile.
From that point of view, I wouldn't mind the arguably over-powered abilities being rare and expensive. It would make things more interesting.
