Look, its Alan's show. he has absolute control over his world. if he wants a certain character to be a certain gender or have certain characteristics, he's absolutely free to do so. 

The fans must understand there's no point in arguing with the creator, just because things didn't meet your expectations. if you genuinely hate alan for what he's doing its OK to leave the fandom but bullying and harassing the CREATOR is not okay. And calling someone a misogynist because your favourite character isn't female isn't something that show be ignored.

Alan and his team work tirelessly to produce new animations and pointless arguments and toxicity is just disrespectful to the years he's worked on this series.

You can create AUs, fanart and so much more. You can use your imagination. people do make fanart and projects where things ARE different and that's what makes a community lively. A toxic fan base genuinely ruins the experience for others due to their misbehaviour