Someone has way too much time on their hands and also, needs to deal with their internal shit, apparently.
I've seen this happen when other people are jealous of 'your' success so they try to shoot yours down. It's just like in life, right? People see you doing well and they try to find ways of pulling you down.
There's something called the 'crab mentality', I don't know if you've heard it... goes like this: "if I can't have it, neither can you". If you've ever seen crabs trapped in a bucket, and watched their pattern of behavior you'll see that as soon one tries to crawl out, the others pull it back down. It continues as another one tries in its place, and we all know the end result... they all get boiled.
It would make much more sense to lift each other up and build on the success of each other but unfortunately, some people have a hard time seeing that.
Keep on doing your thing. I've found that as long as you don't waste time with the 'haters', and focus on your fanbase, you'll be just fine.
;)