I doubt that, why would websites recommend long passwords if they're just as inefficient as shorter ones as you claim ? In that case, who cares about long passwords ?
That simply isn't true. I'm no expert of course, but I know that with 20 characters, there are quadrillions of combinations (I don't make the maths, I'll let you do it if it bothers you), making it impossible to crack, even for a machine and a life time isn't enough to crack it, and even if it was, finding another way to enter would take less time than find it.
Length is much more secure than "complexity" (adding $ and otehr &, %) onto a short password, it's good, but not enough and won't be as efficient than using normal alphabet, random at best, with a 20+ long password.
