I'm exactly the same. EB competing in the male category, where EB belongs, in whatever kit and hairstyle EB prefers......100% cheered on by me. It's clear from the images of the male cycling team EB is part of at university that this is not a problem for any of the others on the team. So what's the issue? It's not non-acceptance, is it? It's clearly not that they make EB feel unwelcome or threaten EB in any way, what with sharing facilities etc. So why doesn't EB want to continue to race with them?
It just stinks of "I WANT I WANT I WANT".
I actually think EB's mother (female parent, bore a child, absolutely 100% adult human female) is partly at the centre of this. Sports parents often put their lives on hold to support their child and it takes a lot of money and time to support a cycling child. Parents seem to almost bankrupt themselves ensuring their kids have all the opportunities they could get, and I doubt EB's parents are any different. It may be that some parents don't accept it when their investment / child doesn't make it as far as they feel they ought to, considering the sacrifices they've personally made. It's not a huge leap to imagine one or two of them grasping at anything they can do achieve their imagined "right to succeed". Competing in a different event may well be more suited to their child (an excellent swimmer who doesn't make it in the pool may move into triathalons, for example). Competing in a different sex class is probably viewed as just another opportunity, especially if your kid is ambivalent about their personal identity.