I've always considered TOS's an abberation of contract law myself.
I've had many professional contracts with both private and commercial clients. In none of those cases was I ever allowed to provide a contract where I could just decide whatever I want, whenever I want and the customer is forced to agree otherwise...fuck them...and I still get paid.
The TOS are subject to change but at least here (France) tout have to be informed about the change and you can leave the contract at no cost of you do not agree.