Until it gets made into a law, he simply doesn't have to. Would I love to see it? Of course. But this administration has been playing by it's own set of rules from the beginning, as promised in their campaign.
This is just another example of how much better at politics the GOP is. Obama wants to appoint a SCJ, turtle dude says 'No' and it sticks because there is no law saying he has to. Trump refuses to release taxes, liberals get mad but ultimately no law is broken when he doesn't, so he won't. Trump repeatedly funnels government money into his resorts by staying there every other weekend, but there is no law saying where the president has to stay. I'm positive there are more examples but you get the point.
His supporters and his 'I don't support him, just his policies' (supporters) don't care about these things so long as he sticks to the party line. So until (big IF, mind you) the Democrats wield any power, expect more of the same.