B-sticking is pretty much a retreating special attack. If you set your c-stick to special attacks and press back on the c-stick while holding forward on the control stick, your character will do the appropriate special, facing your current direction, but receive some backwards momentum. This can be accomplished without "b-sticking" as well.
To break down what is happening, first your character initiates a turnaround B by pressing the opposite direction and then quickly using a special, in that order. Then, your character does a "B-reversal" (working name, not of my choosing) which reverses the direction of your attack AND your momentum by quickly changing direction again AFTER pressing special. So to do without a b-stick, you press back, special, then forward again. Turnaround B reverses your direction only, then B-reversal switches your direction and momentum, resulting in a retreating special.
That said...
I agree that the argument that Melee took much longer to develop ATs is not a usable one when discussing Brawl. At the time of Melee's release, there was a significantly smaller fanbase, no unifying community like smashboards to promote sharing of ideas, and an even smaller fraction of the fanbase that would've made any effort to search out ATs immediately. People weren't that concerned with it, frankly.
At Brawl's release, there was an ENOURMOUS carryover fanbase from Melee, as well as a sizable new fanbase. There already exists a very large competitive crowd interested in finding ATs fast, and a wealth of information sharing in various online smash communities, like smashboards. There are thousands of users, both old and new, investigating every aspect of the physics engine they can think of for potential exploits. People know what they're looking for, and they know how to look for it.
The two situations are not comparable. While I by no means claim that nothing new can or will be discovered--I certainly believe new things will still be coming to light for years, it is by no means guaranteed that we will reveal ATs as gamechanging as anything in Melee. We are discovering potential exploits and peculiarities of the physics engine at an alarming rate, and at an equally alarming rate, we will eventually exhaust most possibilities.
The mere possibility of the existence of ATs undiscovered does not guarantee their existence. The argument that because Melee ATs were discovered slowly and sporadically, there will always be gamechanging Brawl techniques still to find is absurd. People weren't looking anywhere near this hard for ATs in Melee.
We're in a completely different situation, and blanket dismissals of the reality of that situation aren't logical.