I never understood this argument by anyone, about anything. Parents are hypocritical for trying to prevent their kids from making the same mistakes they did? Honestly, that's the argument you most often hear from the teenagers themselves.Think kids shouldn't smoke, and yet when you were a kid you smoked, I'd be extra careful with your judgments on that.
I don't know how any thinking person would criticize me or any parent for not wanting my kids to have lots of unprotected sex, do really dangerous drugs, drink to the point of blackouts and drive, or any of the (long list of) other stupid stuff I did as a teenager. That's actually a big part of what being a parent is - taking the knowledge of learned experiences and wisdom, and helping guide your children's lives to be better than yours. It's not hypocrisy at all.
Following that logic, there aren't any adults out there that didn't pee and crap their pants at some point as children. Yet, we hypocritically choose to potty train our own.