It already has to some clubs - 41 have been penalised by UEFA some with suspended exclusions from tournaments and others have already been excluded.
Yes, and for over 100 years the registration of a footballer was retained by the club, even though the contract had expired, until it was challenged by a certain Mr Bosman (have you heard of him?)
It is just that they (UEFA) have not yet challenged the one club who will stand up to them (i.e. a rich one)