I and most of the members in my crew never use catchup because it doesn't make for a "clean" race since the easy catch-up ability makes people say "fck it" and ram whoever might be in first at the time.
And i've found that even with catchup off you can still catch up from last if you're talented enough! Imo catchup is completely useless and just helps ruin the gameplay experience for actually racing clean.
Look at it this way, if a racer is in 1st and doesn't crash the ENITRE race and takes every turn perfect, doesn't he/she deserve to win as long there isn't someone "stalking" them in 2nd? When catchup is off it allows for the race to filter who is better than others in taking turns, dodging traffic, etc. and whoever comes in 1st, 2nd, 3rd, is basically then representative of who actually did the best driving that race.
When catchup is on none of that matters, because someone who f*cked up on 5 turns can still weasel their way to 1st easily.