I think you have run into the problem many of the curation accounts have run into. People see the opportunity to get on a list and to get rewards, at first they will try real hard to get there, and then once the rewards start to roll in from the curators they just slack off on effort thinking that any effort at all would get rewarded.

Do not vote on those you feel are below par, vote on the good ones reward the excellent ones. People will eventually see what is going on and will adjust or will leave and find another mark to take advantage of.