My post was about one specific aspect of blind methods, that is, the speed. What I meant is that there is no debate about OP being slower than the intermediate methods.
But of course OP is a very good starting point to learn the fundamentals, in fact I would recommend starting out with OP to any beginner!
While M2 was a very good stepping stone a few years ago, nowadays I don't see why anyone should use it. OP is enough to understand the fundamentals, after that you can maybe learn edge comms directly, or some sort of intermediate method that is better than M2. Remember, something like U2 or Orozco is just as easy as M2, but slightly faster and teaches you many things that you want to learn about 3-style anyway (in particular, you get to use the correct buffer from the beginning, and you get used to a variety of slice finger tricks that you wouldn't with M2).
Of course learning Orozco is never a waste of time, because it's a strict subset of 3-style. It might help some people with their transition to 3-style. Certainly, some people's progress might also be slowed down because they stay too long with Orozco without transitioning to 3-style. Still, it's a nice tool that might help some people, especially those who are intimidated by 3-style and still want to get there.