Definitely cannot argue with the results.
You can argue a lot about the results. I call into question her methods and her success as measured by looking at her clients 2 years after they stop her program.
If someone needs to lose over 100 pounds, they need to lose it slowly for a variety of reasons.
Most of her clients gain some, all, or even more weight than they lost once they step off her ill-planned program. The body fights back against vigorous reduction like that and resuming even a normal, healthy lifestyle is going to see them gaining back some weight rather quickly after what they've done to their metabolism. It's compounded by the fact most of these fatties never really mentally get into what they need to do, they're still in fatty land but just took a fitness vacation.
An aggressive 2 pounds a week for an entire year shows dedication. You learn nothing by dropping 100 pounds in 2-3 months because it's over so quickly and you adapt to the shitfest that is living under that sort of heavy CR and exercise by telling yourself "well, at least it's over in X weeks". Sets them up to fail from the start.
There will be setbacks, there will be holidays, and there will be (un)planned cheat meals/days. Instead of 50 weeks losing 2 pounds a week, it may be 8 weeks losing 2 pounds followed by 2 weeks of negligible weight loss. Hell, sometimes this happens even when they think they're following the plans due to mismeasuring calories. Dealing with failure is part of the learning process of not being a fatty.
Finally, there is the ultimate reason fatties fail: most of them look like shit with their clothes off even after losing all their weight. Sometimes with the loose skin, it's even worse looking than when they were a land whale. Surgery is incredibly fucking expensive, there may be additional stretch marks and scarring that can be hard to treat and also expensive, etc. This can be mitigated by proper strength training and milking the beginner fatty gains where they get to be the only naturals gaining muscle and losing fat simultaneously. Ultimately though, they're never going to look as good as a skinny guy/gal who intelligently bulked up, and that can be heartbreaking.
So much of fat loss for the average fatty is mental, and Michaels basically fucks them without lube in terms of preparing them for reality after her program. Failure of a trainer if you ask me.