I think Dane Cook got so much hate because he had a couple mediocre movies then got accused of stealing jokes. I think the joke stealing accusations and other successful comedians subsequently shunning him, combined with having a few bad movies just made him lose out on better acting roles and headlining bigger venues. He just sort of dropped off peoples' radar. I don't think the accusations of him stealing jokes were ever really substantiated, I think it was more that some of his bits resembled some other comedians bits.