By the logic of your friend Mr. P, I should be able to turn on CSA and run 1:37.9 (1 second faster) which would have made me one of the top 3-4 players in the western hemisphere. A nice thought, but highly unlikely. If it ACTUALLY gave me that benefit, why wouldn't I use it?
I never used CSA on strong or weak. Also, most lobbies that I play in don't allow it, so what benefit is there to gain a skill that I then have to go without in the lobbies? I have tried it and I have yet to find it a benefit. It has only ever been a hindrance. As you say, it is a safety net at best. People who are seeing huge time gains with CSA enabled aren't driving very well anyway.
So this goes round and round. The only people who use it for advantageous purposes, aren't that good. Good players who use it, use it for comfort rather than for speed.
The #1 reason people crash into others is poor driving, aka poor car control, and the thought of taking away a car control assist from poor drivers seems extremely counter intuitive.