I think a big part of the hate came from the fact that the developer was charging for a premium version. Lemmy is all about open source, power to the people kind of things, so I imagine this rubbed people up the wrong way. Plus it was a fairly popular reddit app, and people were hating on the reddit refugees as well.
I read it more along the lines of the one on the left is the coding transgirl stereotype and the one on the right was the artist transgirl stereotype.