I guess on Hive large stakes will always attract extractors, rewards farmers and all kind of people interested more in the rewards than the content. The only way to avoid that would be not to upvote comments, but this would nullify one of the best part of Hive, i.e. rewarding meaningful and sincere engagement... so I'd keep going as you always did, without changing anything. I always find your posts full of "real" comments, so it looks like your way of curating comments has already proved to be extremely valid.