Fun fact - terms and conditions are not legally binding. They are only a guideline that you must follow to use the product; so long as said terms and conditions abide by law, and they only apply going forward so long as the consequences for breaking the terms and conditions are also legal. In other words they can't make you do anything - they can only tell you what they will do if you violate the terms, and they can't make you, the user, do anything.
If a court one day says that you legally own the games you buy, all of these terms and conditions are legally null and void, and the company is in violation of the law if they revoke access.
Edit: in addition, if you buy a product in the US and sign a version of a contract (terms and conditions) and they change the conditions you are only beholden to the original conditions unless you consent to the new conditions. If you own the product they cannot take it away from you. This is why they are so insistent on you not owning anything.