I don't care for the idea myself to be honest. To me part of the point of an RPG was to try and solve problems from a certain perspective, and find a way to apply what skills you have to overcome the challenges. When you go the way of a lot of single player RPGs where the protaganist can do everything, and the big question is what order you develop the skills in and what you choose to do, I think it lowers replay value, and removes the aspect of the game of trying to apply what you have to the situation at hand, rather than simply developing whatever skill you need to bypass a problem in the way you deem most efficient.
Now, in a tabletop game I can see why people want more rounded characters as there is a lot more going on, computer games are more limited by the medium. What's more the greater depth of activity in a PnP game raises questions about how characters that are totally single-faceted can survive in day to day life, when say a regular warrior isn't likely to have the skills he'd need to repair the thatch roof on his own village hut. In a computer RPG though questions like that are never likely to come up. "Multifaceted" in this case being along the lines of making everyone a warrior/thief/mage/cleric/druid/ranger/paladin/assasin/bard/ninja with the only question being specifically how good the character is in every area. The odds of say the character not being able to pick locks (since it would require giving up other things) is unlikely to arise, thus finding ways of dealing with problems like locked doors and chests (where bashing them open can destroy items or alert monsters) are unlikely to occur. What's more it also means that the game developers can assume every lock will be picked so doesn't need to work on alternative things like destroying doors or chests.
I can understand where they are coming from, but I think character classes became a staple for a reason. One of the things that helps make a game replayable is to say beat it as a mage and then wonder if you could deal with the same situations using a skill set your not as familiar with/used to. I mean you know a Thief type can beat the game, but can you do it? Then if you've beaten the game as a mage and thief and relied heavily on sneaking/invisibility, what about playing as a warrior who doesn't have those kinds of options?