I like being on the bleeding edge. My only Windows PC is a gaming machine, so I don't mind it updating frequently and/or needing babysitting (for example, the very latest flight added a HyperV adapter and broke my internet, despite having HyperV disabled).

That, and honestly, they're pretty rock-solid. Other than this net adapter this thing past week, I've never had anything truly disruptive. OTOH, there've been a time or two that I was glad to be an insider because of a bugfix or feature that wasn't likely to be backported to stable.

And some misplaced desire to help? I can rationalize it with OSS, I can't really tell you why I feel some sort of responsibility to do it for Windows too.