The quality probably has gone up, maybe not too much but it'd be a sad day when the general quality starts to go down. Sniping may be on the increase as the site gains more popularity, since I've been on the number of people posting pics has doubled. That brings it to more peoples attention, mostly good but it will draw some bad along as well.
If it's recent voting scores that you are on about it could be because it's the school holidays.... therefore more bored kids with nothing better to do with their time than try and mess up public voting systems... especially if it's something "sad like painting little metal men". Well if the best use of their time is to mess up a public voting system then that in my book makes them far more sad than us.
@ funnymouth - keep posting pics on here despite the voting. Think of it not so much as must get a better score, more sharing your work with the rest of the world regardless of the votes. Yes the voting is in a way important, otherwise it wouldn't be part of the site, but don't hang your life on it ( not that i'm suggesting that you are mind).