They could give you access to your old games whilst restricting your ability to purchase new ones. The fact that they don't is strictly their anti-consumer choice.
You are continuing to use the service even if you don't buy new games. Since you are using the service you have to accept the EULA. There are no two ways about this. Not accepting Steam's subscriber agreement is not the same as getting banned from a couple of games.
This is ridiculous. How is anyone to know which clauses will be upheld?
That's what courts are for. If you think a specific clause that is enforced upon you is illegal, you take the company to court. The fact that you clicked "I accept" doesn't matter one bit.