Even if it hadn't been adopted by white supremacists (it has), it would still be abhorrent.

yes, it is abhorrent… it’s not, however, a white supremacist symbol.
“crusader” is a terrible term for the military to associate itself with… but definitely not as terrible as a white supremacist symbol.
white supremacists have also “adopted” wearing boots but i’m not going to call everyone wearing boots a white supremacist.