I don't really agree, but I sorta do.
I do think there are blaring balancing issues, however I easily climbed to top ranks with a sorta f2p mech (I had some BD reds left around and I had an account before SM reloaded, altho it was lvl 9)
SM reloaded WAS a step in the right direction for f2p players, but then the SM team imo took a step backwards with the bigboy and item box nerfs. I was able to grind campaign and bigboy before the update and every time I got faced with an issue winning in arena I was able to grind it out for a bit to build my mech up to be even better. However with the death of the good farming methods it's kina killed my motivation to play. It's a lot harder to get higher now.
tldr: I don't think the matchmaking necessarily sucks, I just think the way it's set up has been messed up with the fairly disappointing changes to the game.