Actually... Sega's own previous flops killed the Dreamcast - not to mention Sony's Playstation 1 and 2 - both of which were probably pirated more often - which helped boost sales, not kill them.
Check out http://www.eurogamer.net/articles/dreamcast-a-forensic-retrospective-article for a really good article on the true reasons Dreamcast failed.
My point really was that piracy would be a bigger problem than non existing emulation, but didn't properly said that. I've always said that what killed the Dreamcast was the exaggerated Sony hype. And use the example of my cousins being absolutely blown away by my Dreamcast, more so than any console jump that they had experience, since they were used to the PS1. But that such a reaction did not sell a Dreamcast, but rather made Sony upcoming "Supercomputer" an absolute must have. (I remember one article insinuating that the PS2 was going to be more powerful than like ten PCs.) Made me disgusted with how people are affected by exaggerated marketing.