It's not the trans high school student just looking for a comfortable place to use the bathroom, it's the horny teen males who now have a legal right to be in a place where teenagers of the opposite sex are unclothed and/or showering.
A legal right? Really? You seem to be very confused on this issue.
It has never been illegal to use the "wrong" bathroom. It has been generally discouraged, but there is no law against it. I've done it, in places where it was necessary. I'd wager you have too.
What IS illegal is assaulting people. In bathrooms or elsewhere. By videotaping them or in other ways. Those things are already illegal, and this new law wouldn't have made them any more illegal. What you're asking is for people to be legally prohibited from being allowed into a position where they MIGHT commit a crime that is already illegal.
You might as well make it illegal for black people to drive because they might commit a DUI. You've singled out one group, you've made something illegal that shouldn't be illegal, and you've not provided any additional protection against something that is already illegal. So what's the point, if not to discriminate?
We're giving a legal defense to these predatory males to be in a place ripe with opportunity to scar a woman or a child for a lifetime.
See? You've even admitted it. You're saying we need to criminalize the opportunity to commit a crime (that is already illegal) for some subset of the population that is not otherwise doing anything criminal.
As an alternative, how about we stiffen the enforcement or penalties for actually committing the crimes we want to discourage? Banning black people from driving cars doesn't make any sense either.
You've probably already shared a bathroom with a trans person at some point in your life without even knowing it. Why put that person, who is already facing a lifetime of discrimination and hatred, into a situation where their very biological needs are now legally scrutinized? Why not let people (all people) have the privacy they desire when conducting their bathroom business?
If you object to sharing a bathroom with someone over the opposite gender because you are ashamed of the fact that you poop, and most Americans apparently are, there are lots of solutions available to you that do not involve actively discriminating against people who are doing nothing wrong except making you uncomfortable by being alive. People like you, trying to criminalize using the wrong drinking fountain or sit in the wrong part of the bus, are the ones who will have to change for our country to adhere to it's stated ideals of equality and freedom. Sorry.
Or, you know, we could just make all the trans people wear a big yellow star on their chests. Just so that we can easily identify who they are, in case we need to round them up in the future for some reason. Does that also sound like a good idea to you?