Studios, companies, and teams typically try to guard against bad behavior–especially from their youngest stars–by loading up their contracts with so-called morals and behavior clauses; such provisions give the execs a legal out should they decide to cut ties.
A morals clause is part of a contract that defines certain behaviors that are unacceptable to a party. If the conduct defined in the morals clause comes into question, then the contract may be voidable or subject to termination. The reasoning here is that the party contracting with the sports figure or film and television star has been subjected to conduct that is detrimental to their interest; or it devalues the performance due under the contract.
Historically, morals clauses have been thought to be too vague to be enforceable when drafted in a catch-all manner–like “X may terminate this contract upon written notice to Y if Y shall at any time fail, refuse, or neglect to conform their behavior to the moral standards of the community.” Doesn’t that clause just feel too sweeping to have any effect. Nobody should be able to define what a person can or can’t do in their personal life right?