There are a few of us out there that know what we're doing (as far as counting) ... most do not. Shit, I find that most people that claim to know BJ basic strategy only know about 80% of it.
BTW, it's a common misconception that counting a 6 deck shoe is much harder than a single deck. It's really no different. You're always keeping a running count, and then dividing by the number
of decks remaining to get a true count. If anything I'd think people would have a harder time dividing by a fraction (in the case of single deck) to get the true count...
Have you ever heard of a unbalanced count ?