But, what characterizes the historical Renaissance? Yes, if you want to get pedantic, it's rebirth, but, what elements do we generally (and I'm using a pretty broad brush here) in art from this period?
Is it characterized by highly trained, professional artists who go to schools in order to learn their craft after years of training under a teacher? Or is it characterized by highly talented individuals banging out loads and loads of material, the vast majority of which is forgotten (or only remembered by very small numbers of art experts) and a small number of talents rising to the top above the crowd?
I'd say it was the latter.
Look at how design has changed from before about 1995 (give or take) and post. In the early days, it was one or a small number of people putting together a game, almost in the absence of any marketing or any other outside input. Heck, TSR never bothered to ask anyone how the game was being played for the entire time they published. I can't imagine FASA or anyone else did either.
Now compare that to how games are put together today. Not just 4e and 3e D&D, but, generally any game that hits print. You have marketing teams, you have legal teams, and various other hangers on putting this game together and getting it onto a shelf. ((now, team might be one guy, that's true, sometimes there really is an "i" in team.

))
Erik Mona and Pathfinder is a perfect example. Compare how Pathfinder evolved from 3e D&D using the OGL, bringing in tons of people, and Palladium, a game that evolved from 1e D&D and used about one guy.
Note, through all of this, I'm really not trying to make any judgements. It's not old=bad, new=good or the other way around. Renaissance art is not better or worse than modern art except in the eye of the beholder. In the same way Renaissance games (pre-early 90's) are not better or worse than Post Modern ones. Please, don't try to see this as a criticism in any form. It's not meant to be.