The strangest thing, the thing that immediately had fans in an uproar, was that he said that the turtles were aliens.
Now, considering his defence (linked above), lets assume that he genuinely is changing the origin of the characters.
Some responses I have seen are along the lines of "Hey, relax, aliens make just as much sense as mutants."
But do they? Really?
First of all, consider the name of the franchise - they are ninjas, mutants, and turtles. If they are aliens, they would have to be alien mutants, alien ninjas, alien turtles.
The original story was a reference to the origin of Daredevil, because the creators were huge fans. A chemical spilt on some turtles, which mutated them into being anthropomorphic. It also mutated a human ninjustsu master into an anthropomorphic rat. The rat then taught the turtles ninjutsu, hence why they are ninjas.
Let's call that 3 on the ridiculous scale, 3 ridicules (Turtles mutated; human mutated; human-rat teaches turtles).
Now, what if they are aliens? Then they have to be aliens that for some reason look like turtles. They also have to be taught ninjutsu by a rat, who is also presumably an alien. Then they came to Earth. Also, they have to be mutants.
I'd say that's a solid 6 ridicules (aliens that look like creatures from Earth; alien that looks like a different creature from Earth; Second alien knows a martial art from Earth; Second alien teaches first aliens; Aliens come to Earth; Aliens are also mutants)
I therefore disagree, on the face of it the origin stories are not equally silly - they alien story, the one that annoys the fans, is objectively twice as silly as the original.
I would say "I hope they don't mess it up" but let's face it, it's Michael Bay, therefore it will be atrocious.