You find docs on both sides of this issue (and some VERY passionately).
Bill Dorfman one could argue has helped the vast majority of restorative dentists practicing today do more work. His mainstream exposure of what the profession can do for the appearance of one's teeth (both in his Extreme Makeover(EM) segments AND via the maasive amount of print and TV advertising his Discus Dental Company has done over the years) without a doubt has increased the interest of a good deal of the general public in "cosmetic denistry" which has led to THEM (the patients) asking their dentist about what they can do to improve/enhance the appearance of their smile. And that's been a GREAT thing for the profession that just about everyone can agree upon.
On the flipside, Bill Dorfman (and countless other "cosmetic dentist guru's" for that matter) many will argue that they've done more to overtreat and destroy plenty of prime, healthy enamel/dentin in the name of a quick buck and a quick fix. With respect to his EM segments, at the time of the show's airing, there was tons of online dentists debate about should he even be doing cases like that on patients like that where those patients will likely be facing large future dental bills(without the folks at EM covering them) for when some of the work inevitably fails since the underlying cause of the habits that got the patients in such poor dental health in the 1st place were never fully addressed. And then there's always the debate about the large veneer cases to "quickly" correct what in many pre-op photos is a mouth that one could easily argue that the best LONGTERM treatment is orthodontics and maybe some bleaching.
He's a polarizing figure in dentistry for sure. I will say though that having seen him speak twice over the last decade or so, that he's a very entertaining speaker, who inspite of all the "famous" mouth's you see in his presentation (last time I saw him about 4 or 5 years ago I think I saw close-up intraoral pics of about a dozen Playboy playmates and an equal number of hollywood actors/actresses) comes across as a down to earth guy.