I was there, I’m Muslim, and I’ve also been a construction worker. The contractor is Muslim, and we put the flag on there because we like this country. I hope you’re not disappointed! :)
Most of us don’t like the current administration, but they’re about to leave anyway which is an example of the good things about America! What is ‘America’ today may not be ‘America’ in four years, which is a constant source of both fear and hope for all of us I think.
And you may also be interested that I heard a lot of spontaneous complaints about the shame terrorists are bringing to our religion as I was walking around. Maybe you should come when we build the next mosque! :)