I understand idealogically what you're saying. However , the words Make America Great Again are actually not fine on their own at all. The words All Are Welcome obviously are fine on their own, as you said, because they dont not recklessly harken to the past.

I think a better comparison would be to say it's like banning the color red because it's also the color of blood/gore. Politicians are actively making a battle out of rainbow 🌈 coloring. Which is so silly and a waste of time because a rainbow also happens to be a useful set of colors in a school ground, whether paired with welcoming words or not.😂