It's not just about impressing people. It's as much if not significantly more about angering people.
Even if the decision by Trump to bar trans people was incorrect (along with many other things), the legal decision is probably valid. The US military is by necessity generally separate from the constitutional protections it is intended to protect. The 1st amendment being the obvious example. It's hard to imagine equal protection under the law being strictly applied to an entity that arbitrarily sends people into combat. That being said however, the military and especially the CiC should better try to apply the principles of liberty in our country to those serving.