One glaring problem with dynamic queue

The problem i foresee with dynamic que is that it will end up with the same problem teambuilder often had waiting 20 minutes to find a support.

I see alot of complaining by people who select support/fill as secondary tthat they get the support role over 90% of the time. And the only way to avoid this is by selecting a different role as secondary so we end up without supports again.

However there is a secondary problem, when people select their secondary, mid for example and get that role while not being any good at it it hurts their team aswell.

So we will eventually end up waiting forever to play a game were there is that one guy feeding the shit out of his lane opponent in a snowball meta. . . I don't really see how that is a healthy state for the game.