I was in the fandom from until sometime around the gap between seasons 2 and 3.
S1 and S2 were genuinely funny (albeit with some annoying parts – I always mute the songs), but S3 was crap, and the fandom got too obnoxious for even me to stand around that time.
That said, some of my best memories are in the early fandom, and I've made friends there who've helped me through some extremely tough times.
Kids' shows really should do their best to appeal to parents as well because kids will force their parents and older siblings to watch their shows as a captive audience. That's just how little kids are. They don't understand the concept of other people not liking what they like. And, for a while, MLP was a genuinely entertaining cartoon that the forced older audience didn't have to suffer through.