It started as isolated incidents, but it is now a huge issue because the current wave of people identifying as trans has all the makings of a social contagion and it's spreading like wildfire.
With things like these you have to stop them before they become a massive problem. Why wait until it becomes a gigantic issue when it's clear that it will already?
What a ridiculous thing to say. People have been able to look at another person forever and correctly say what sex they are and be right 99.9999999% of the time. The only times people were wrong were when they had a very specific DSD. Those people are the exception to the rule of being able to tell sex simply by looking.
You're basically saying that what someone is biologically is irrelevant, what they look like is what determines their sex. That is so incredibly sexist that it's hard to even believe anyone could believe it, yet here you are.