Easy way to tell some is ignorant about Elo/MMR.
They cite gameplay as proof of an mm issue.
"Feeders, one sided, snowball, trash top, garbage add, jungle diff," not a single one of those terms has any relation to the mathematics behind Elo or it's derevitives. Its like some one screaming at a mechanic they want their car to have a quicker 0 to 60 so they demand he replaces the break system with better breaks. A basic understanding of a car is all you need to know to point out that upgrading breaks will not enhance acceleration.
If folks truly want to discuss MMR and what riot can do for improvements you should see terms like " probability, curve, distribution, class interval, K factor, system expectations, avarage,Range."
RN=Ro+K(W-We) if you cant read that as english please wiki Arpad Elo.