Slap in whose face? No one's face was slapped. Nor was anything disrespectful about the flag or anthem even said.

It is simply your opinion that the silent protest is disrespectful to the country. Perhaps, most importantly, why would a silent non violent gesture, even if some people see it as disrespectful, be such a big deal that the POTUS has to weigh in by suggesting the people protesting should lose their livelihoods?

What is your opinion about being told by the POTUS that a silent protest should cost someone their career?

Is the USA so thin skinned that a couple of football players kneeling during an anthem requires an outburst by the POTUS???

I can tell you that hundreds of professional athletes are more than just a little cheezed off about being told they are not allowed to express themselves freely and some of them are from military families, I might add.