"User License Agreement", ie, Contract. In order for a contract to be valid, a few things have to be true, in this case, the contract has to be legible/readable, and the other party must affirmatively agree to it. (This isn't an argument so much as just fact, which I'm sure you'll agree to).
I'm going to argue that most EULAs represent a "sticker contract", and would typically be considered non-binding because they fail to be readable by any average person and that no affirmative consent is given. Legally, EULAs may or may not be legally enforceable in different states. South Carolina considers EULAs not-enforceable while some states may consider otherwise. From my own reading of the law, I think any "Here's a long complicated 20 page essay on how you don't have rights, written in a foreign language, click 'I Accept' to install" type thing doesn't constitute an actual legal binding agreement - YMMV, it's usually up to the court in question.