Jeez, i have repeated this like 4 or 5 times. Im always talking about rating races, not a normal public online.
You still seem to think a rating system solves everything. It doesn't. Someone with a good rating can decide to go 'rogue' for one race every now and then and it not have a huge affect on his overall rating. Someone with a good rating can still pass his controller over to his kid brother or friend for one race. Still bad for me if I'm in that one race. Then there are the aspect Slip mentioned that have nothing to do with rating, lag and disconnects. Plus what I covered, wanting a race at any time of the day, there is no guarantee evenly matched, clean racers are online.
Clean online with rating=Always much better AI, much more excitement, just better.
So no, this is still just your opinion. A rating system guarantees neither of those things.