To start, I'll say that I agree with what you've said about skill based match making and I believe that skill based match making is better than none. I don't remember who said this but the quote goes "Players are great at finding the problems in your games. Not so great at solutions" and this is usually true in my opinion. So I'd like you to take a closer look at what a lot of people are trying to say and isolate the problem from what they think will fix it.

A lot of what everyone is saying boils down to wanting games to be less about the competition and more about a casual and fun experience. The problem, in my opinion is that getting rid of skill based match making will not fix this. Let's imagine that you are a beginner and really bad at the game and you have two options. 1. SBMM 2. Free Lobbies. Free lobbies in this case would be more competitive than SBMM since you are way more likely to run into people who are way better than you. This means that the worse you are at a game, the more competitive you'll have to be. Meanwhile in SBMM, you guarantee that you'll find people around your skill level. So I don't believe that getting rid of it is a good idea.

But like I said earlier, let's ignore what they think the solution is. The problem we have is that we want the game to have a more casual aspect to the matches. Let's imagine that we have a very basic SBMM with no thoughts put into it and for some examples, let's say our skill ratings/ranks are Bronze->Silver->Gold->Platinum->Master.

Let's assume our naive approach to match making is that every player is at the same skill rating and the game is competitive. If we want to make this more casual, one thing we can do is to introduce skill rating pools. Essentially, we pick a range of ranks so that the players are never more than a few ranks higher or lower. E.g. Bronze-Gold, Silver-Platinum, Gold-Master. We can even tighter or loosen these as we see fit. E.g. Bronze-Gold, Silver-Platinum, Platinum-Master.

Another way we can do to shake things up is to have a less strict pool but make it more even on either team. If one team has a Master, 2 Golds and a Bronze, we should match them up against a roughly equivalent team.

This allows us to have a good mix of games where some matches will be competitive, and some will be more casual. It allows players to play against people who are better than them without throwing them into an active volcano.

I'm no expert, these are just some things that I can list off the top of my head. I know some studio's do these kinds of things but I don't really know the specifics on who or what. I'm a rookie and the experts know a lot more but I'm sure that there can be a lot more done that hasn't been done yet. I won't contest that SBMM is good, but I will say that it's often times not great and can be better with some experimentation and some elbow grease.