@Cupcake I used to play in a lot of Dreamwidth games. Many of these games can indeed have a 100 or more players. The catch is that many of them will be idle or barely ever post and a good chunk will never have any interaction with you or your characters at all outside of maybe Memes (which in Dreamwidth context are small single purpose posts not considered part of 'game canon'/IC unless specifically stated. Little games like 'post your character, others reply with whether or not they'd date them) or OOC utility posts like plotting, opt outs, or HMD (How's My Driving. It's supposed to be to get constructive criticism but they primarily become people gushing about how much they love their friends and openings to flame and harass people they don't like.)
4+ player scenes are possible but they need A LOT of OOC coordination. The only time I've ever seen them work are when the players get together on instant messenger or some other communication platform and plan the scene in advance or at least give an outline for what they want to do.
I can also say that Dreamwidth's Wankgate is more like the Hog Pit section here run rampant and unchecked than the MuSoapbox as a whole. It's a lot more vitriolic and mean there. Some could argue that could be said about Dreamwidth as a whole actually.