There's some nuance being lost here - they aren't saying they will violate the law, they are saying that their lawyers will advance an argument that the law (ABC test) does not apply to them.
I think the legislature and many on HN believe that courts will think it's absurd that Uber's drivers are doing work "outside the usual course" of Uber's business. I'm inclined to agree, but I'm not a lawyer and I don't know how well written the law was or whether California courts will include legislative intent in applying that language.
