they're presenting the idea that some people might be less confused and make different life choices if more people tolerated traditionally-gendered subjects (like clothing and makeup) from anyone without judgement

The problem is that a gender & sexuality based on a spectrum makes it extremely hard to define things, which is something humans just naturally do and why we ended up with the binary way of it. But if we have a spectrum ranging from masculine to feminine, then we suddenly have not just trans people, but also those who may identify & look like the opposite gender, but don't want to fully transition (i.e. keep their birth sex). You basically have anything in between the two binary categories now, and that is consequently muddy on top of being new and foreign for most people and even often within trans communities. Doesn't help that research on those topics is also still fairly early and definitions can change rather quickly at times, making it hard to keep up with it.