Some random remarks.
First of all, I should say that my original piece was a response to Rob, and not intended as a rebuttal at all. It's literally a case of 'Rob said this, and then I thought this other stuff, and wrote it down.' I fully support Rob's right to his opinions and ideas, and I don't think he's wrong on any single point, here. We arrive at somewhat different conclusions, but I think we're lot closer together than one might imagine.
Secondly, Rob IS throwing out a bit of a fallacy with the 'professionals don't critique' since what he means by 'professional' includes 'doesn't teach' which is.. dum dum DUMMMMM... Begging The Question. But that's ok, I see what he's driving at, and once again, he's basically right. Professional mathematicians don't teach, they're busy. That said, they'll probably offer an opinion if someone walks up and asks them for one.
Thirdly, the only correct response to being given a suggestion on how to shoot a thing better is 'That is the dumbest idea I ever heard!' but the value comes in the next thought, once the juices are flowing, which in the best circumstances is '... but, now, this OTHER thing.. that's a GOOD idea'. Bouncing stuff off people, and getting their idiot replies, can trigger the most wonderful stuff. When I offer critique, I fully expect you to lump it in to "another idiot reply" and I hope that, from time to time, I stimulate an original and good idea in you, that is fully your own.
Fourthly and last, I lied. I do disagree with Rob on one point. Commercial photographers are 99 percent a bunch of fad chasers, by necessity. There's no "critical eye" there, there's just endless evolutionary copying. The client doesn't want your damn original art, they want a bunch of photos that look just like Those Photos they saw over there, but a little bit different. Yes, yes, they SAY they want truly original stuff, but they're lying. This doesn't mean commercial work isn't real and worthy. It is, it's real work, it takes real talent and ability, and a fair bit of luck, to make it happen. But it's not the real home of the critically important thinkers. Maybe Rob is talking about the 0.01% of commercial guys who launch the fads, or something? I am willing to believe that there might be a small population of actually interesting guys in commercial work, but I haven't run across them.