There seems to be a lot of controversy surrounding the OSR movement. Accusations of elitism or of neglecting core aspects of what makes Dungeons and Dragons D&D fly fast and furious. There is a whole blog devoted to picking apart OSR dungeon and module design (Your Dungeon is Suck) and almost everyone that gets sent to my own blog from rizon.net where we run 10th Age games comes back full of tales of woe about the future of the hobby because of how exclusionary and elitist the Frothing Mug is.
I think that's a misconception about the OSR as a whole. I wouldn't even necessarily consider the Mug to be part of the OSR movement as it is focused on things that are decidedly outside of the scope of most OSR sites. Is there are a Middle School Renaissance? Is there a Second Edition AD&D Renaissance? Not that I know of.
I read a lot of OSR blogs and one of the things that strikes me as a very common cord is humor. The games that most OSR people run are filled with jokes and light-hearted monsters that are clearly not meant to be taken at face value. Many OSR leaders reject verisimilitude in setting, others characterization, and still others the value of comprehensively fleshed out worlds. These are things that are very dear to my heart.