Yep, when the pinnacle (or at least most successful and familiar) example of your industry, GNC, is 95% full of products that are either indecently overpriced, misleadingly marketed due to the fact they will do nothing for the well-nourished population purchasing them, or are outright bullshit, then you know you have a snake oil wagon, and that's what the supplement industry is.
GNC is the modern day wagoner with his wares and elixirs.
Maybe the dumbest thing about the supplement industry is that even the few pillars of legitimacy no longer make sense. I remember when Whey Protein was like $2.50/lb. That's great. Protein isn't bullshit. It works. But nowadays even the stuff I see in Wal-Mart is like $25 for 2 lbs. Who on fucking earth wants to pay $12.50 for powdered protein? You can buy Prime Ribeye for that rate at Costco. Hell, you can buy a 3 lb. tube of ground beef with a $10 bill. It's just fucking stupid how ridiculously unhelpful that industry has become to everyone involved, but those shucking the snake oil.