Don't really have a problem with a president doing TV interviews on a holiday. My issue is that with Trump specifically you are dealing with an amoral person who is completely self obsessed, so any time he is given a microphone he will do what every other modern president understood he couldn't do: promote political talking points, sell programs, etc. When Obama was showing up at basketball games he wasn't saying republicans are wack, pass the bills I want, etc.
I also think we need to deal with the reality that...this is the atmosphere. This is the vibe shift. The "new media" is full of Trump fans. We have a TV president who obsesses over coverage, marketing, slogans, etc. He is a salesman/conman. And a lot of people are heavily invested in ensuring he gets to do whatever he wants. Thankfully it seems like the house of cards is falling.