You might be too literal in what you expect to see from S&T players. You know how Moe said things such as "I stick my shoulder into my ear"? Bennett and Plummer have photos showing exagerated moves, to try to get across the feel. And with most students the moves in question have a feeling quite opposite what they've always done. So they probably need the exageration.
Also, Bennett & Plummer make it clear that S&T contains several aspects that can be beneficial to a swing without having to do the exact pattern, if that is what one desires. They also show photos of many of golf's legends in the same positions they teach. Sam Snead's overall swing was very similar to theirs.
I assume you've not tried it, I doubt you've watched their DVDs or read their book. You've probably read the Golf Digest articles, which are quite incomplete, and watched some swings with whatever bias you might have. (We all have them, don't get me wrong.) OTOH, I actually spent some time learning it and had real nice success. If you are interested, I can point you to some internet discussions, unaffiliated with S&T's people, that have the same pattern. Namely, there will be 19 posts of people doing it, saying they've never hit the ball better, then 1 post from someone who has never tried it saying it can't work, this is wrong, that is blasphemy, etc. Then 19 more, then 1, etc.
Well heck, here are 822 comments on it, including some low cappers and independent teachers. I quit reading after 5 or 6 pages, .
Here's an interesting interview of them by Charlie Rose.
You're taking the establishment viewpoint: It can't work. They told that to Moe too. And bumblebees can't possibly fly. I'm glad I tried Moe's swing and I'm glad I tried S&T, despite all the establishment naysaying on both.