I think she wanted to move on and work on her own original projects since she had a good team to leave the show with. 

Wasnt it be cause she wanted to do some episodes classed as dark, like i think she wanted to do one about scootaloo being and ophan or something. But hasbro didn't want to do episodes like that.

It feels weird when I'm trying to make a joke and people take it seriously.

If you like to discuss it, though: Judging by how she acted regarding this, it definitely wasn't her free decision. Yes, it seems like there were unbridgeable differences regarding the design of the show.