They are tax dodgers (why do you think United is registered in the Cayman Islands?).
They aren't British (so didn't have a vote on Brexit, and so you don't know if they supported, opposed, or didn't care about Brexit).
But they did support and give money to Trump, which is worse (and will probably support Trump again, or DeSantis, both of which just compounds this).
There had tried to get investment in the club from Saudi Arabia.
They own a cricket team in UAE.
So yeah, pretty much every example that you gave about them not being morally problematic, was wrong.