The order being reasonable or not is not germane to the topic at hand. It isn't relevant what sex a transgender person is defined to be. What matters to the boycott is that transgender people in tech are facing difficulty entering the U.S. to attend the conference. Wouldn't you agree that's a problem?

Well, reality is more complex then this. It misses intersex as a biological option. Not common, but still, it is not in there, but reality for some humans.

The orders are supposed to "sound" reasonable. If it was obvious what the consequences of the order were to everyone, it would be far less palatable.