[aoila]

A large part of it is that many, many people are getting increasingly annoyed about the concept of "trans" in general. They consider the view that a man presenting himself in a stereotypically feminine manner is a woman to be a ridiculous and sexist idea.

Even more outrageous, to many people, is that men who claim to be women are taking over every space that is intended solely for the use of women. Including in places where it's demonstrably harmful to actual women to do so, like women's prisons, or inherently unfair, like women's sports.

So the backlash and boycott encompassed all of that feeling too. Interestingly this isn't just on the right, as it's often portrayed to be, but a sentiment being expressed by ordinary people across the political spectrum.