Failure to act is as much a “no” as them putting it in words.
The minute you terminate someone you can’t control, you admit to being unable to lead that individual. It erodes at your respect with other team members, and inhibits your growth as a leader. It’s simply poor leadership.
That is utter bullshit. The minute you don’t remove a person who’s a problem you show what a poor leader you are.
If you just allow the shit to fester because “I can change him” you’re actively making it worse for everyone else.