It hasn't happened often, but every time I've tried to remove an owner over MWR, it's been backed by admin. If you can cite the rule broken, show evidence that it's been broken, and the owner can't respond by citing other owners who were given a pass for breaking the same rule, you're set. If you say "This guy's tanking" it's not enough.
Rules have to be clear: "Owners have to try to win at the ML level or face consequences" or "Teams must maintain their minor leagues" are unenforceable.
"Owners must win 55 games in a season or 120 over 2 seasons or be removed" or "Teams must not have 0(0) pitchers appear in 2 consecutive minor-league games at any level or be removed" are enforceable.