While the community could play their job, I believe mods do have to be proactive as well. Most of us don't hang out at the local boards so spams might be overlooked there.
About the badge thingy, it's an interesting addition ngl. Any way to check with theymos about its progress?
Absolutely, I don't think we should be relying on reports from the community, but it does significantly help the process, because multiple eyes is better than one. I do believe most moderators remove content they come across that hasn't been reported, and also report posts that they can't remove.
Last going off; theymos stated it was harder than initially thought to implement, and as a result went down on his to do list. I am paraphrasing a bit there, but I'll look for the quote soon.