I watched the replay. In case I missed the point you were trying to make, here's what I noticed: the lane balance was really weird and could have been better (opti fail? dunno) . Ruler (1000 4v4 rating) made a fatboy on beach, that's weird, right? Surely I missed a lot of things.
Since FTX never bothered to give more details I'll just give my thoughts on both possible scenarios:
If this was a tmm game, opti needs to be more like autobalance at the very least. I think if the lane balance was different the game might have been better. I'm not sure why opti decided 1200 vs 1800 on air was good, or why 1000 vs 2300 in north pond was good, or any other matchup, in fact. Not as good as if everyone had the same rating, obviously. That would be ideal. I just think it's too much to wish for when the player pool is so small and enforcing that too strictly could lead to players in the tails of the rating distribution finding way fewer games, especially 3v3 / 4v4. If this is one of Raider's first tmm games and the rating system is using his global rating as a temporary stand-in for his 4v4 rating, it's understandable why the matchups were so garbage, but that seems like an edge case on top of another edge case: first game of an abuser. Doesn't really scream "typical tmm experience" to me and even with ftx's proposed change such edge cases will exist.
If this was a custom game, why exactly should it not be rated? Everyone participating decided it was a fair matchup by joining and x'ing. The quality was 89%. The ratings are definitely not representative of skill, and 3300 is ridiculous. Ruler's rating is in fact around 1000 on all ladders except global, where they got that high by spamming astro exclusively. The solution is to make ladder/tmm more popular than custom games and bury global rating in a deep UI hole so that players actually have to get good to maximize their status signifier which should be their league badges, not global rating. UI changes to the client and game are needed for that, at the very least, but anything that can increase the popularity of ladder/tmm for the average casual player will help achieve this goal. Banning "all welcome" might help with cases such as Ruler but is throwing out too much baby with the bathwater and the league solution is better and at least 60% of the way there in terms of implementation, meaning most of the back-end stuff is done and some of the front-end as well.