They say that dynamic/flex queue is wrong because you can be boosted but...

By the same line of thought, that also means that you can't be held back by weak players. Put simply, you have no excuses. You and your CHOSEN comrades must be stronger than your opponents, all of them, or you may as well be trash.

The real problem with Flex queue is the misleading name.

It should instead be named something more accurate like SERIOUSFUCKINGBUSINESS queue so uninformed players won't mistake it for something you click on if you just play for "fun" or other things that don't belong in seriousfuckingbusiness queue