10 is a pretty high barrier of entry for only new anime that some people just don't have the time/energy for. Asking people to watch 2-3 anime a season is a lot when some people may only have 1-2 shows they're interested in. Also it'll require people to possibly vote for shows they didn't like just to meet the requirement. There are shows this year like Fantasita Doll or Devils & Realist which I wouldn't want to receive any votes but I'd have to include to get to 10. If you're going to have a minimum it needs to be something more manageable like 5 that way if they watch the 1-2 highlight shows a season they'll be okay.
Still I don't think putting a minimum is going to "fix the problem". There is nothing to stop people from just placing random shows to meet the requirement and there's no way to check to see if said poster watched any of the shows.
I agree that 10 is too high a barrier, but I think 3-5 should be okay. That's 3-5 shows across an entire year, so it isn't really that hard, but it also protects against the point that "how can you call x anime of the year if you ONLY saw x?" Like, right now I'm at 5, I think, but I don't consider myself the norm, given that I watched the majority of new shows during my vacation. I've seen Gargantia, MJP, Valvrave, AoT, and Maou. I didn't finish AoT, but I think getting 20-21 episodes through a 25ish episode run is good enough to judge the quality of the show, barring dramatic shifts in quality at the end.
So yeah, 3-5 is ideal to me, even though I'll probably watch around 10 total this year (Aku no Hana, Pokemon the Origin, Gundam Build Fighters, Coppelion, Samurai Flamenco and Kill la Kill.)