Yea, a lot of the "it's a contract" and "it's voluntary" arguments fail to recognize the huge power imbalance between a label and a band, or any agreement between a single person and a huge company. These agreements are almost never between equals, and are often one-sided and "take it or leave it".

Yes, technically I voluntarily entered into my contract with my ISP, my cell phone carrier, and my employer. But in all cases, it's obvious I'm getting screwed over because of the massive power imbalance. It's a fact of life, but it should at least be acknowledged.