I've tried the online racing a little... and being female & watching what seems to be mostly men race online... winning seems to be tied up with egos somehow. HAHA. As if not having a fast car & being in the lead means they have no reproductive power or something in real life.
No offense, and I'm sure it's not all men... and maybe some women behave like that too, I don't know. But I have a hard time understanding my boyfriend's ideas about racing, so there you go.
it seems to me that a lot of players online will do whatever it takes, including cheating (using a "cheater car" or whatnot), unclean racing (deliberately smashing other cars off the track), or even just outright quitting a race & "leaving the room", just to not lose, or at least not come in last.
So to answer the question "Why are you racing?"
Why do I race if not to win... well yeah, I try to compete, and I wouldn't try to NOT win. duh
But I just like the idea of racing with other real people rather than the AIs sometimes. Plus if you want to experience/practice a track in a variety of cars, the other option is "practice" - by yourself getting no xp & no credits! There's no family cups in gt5!

(
If I come in last most of the time, oh well - I'm still driving, I'm still practicing, I'm still gaining xp & credits. big whoop. I'll do my best to compete, even if I believe I have no chance at all of winning.
If I'm somehow able to find people who race online in what would be considered "lesser cars" or old cars... or you know, one of the thousands of cars offered in gt5... I wouldn't try not to win, of course. I'd do my best there too, & try to win. And if I never win with that either, so be it. I still enjoy the game even though I can't drive as well as my bf does... I'm certainly not going to stop enjoying it because there's thousands of players out there 20 years younger than me that can play better than me. (reflexes slow with age)
I just got gt5 & so don't have many credits yet, don't have many cars... and I've joined races with people ... and some of them CLEARLY do not know the nurburg track.... and believe me I don't know the track very well, so if someone seems to know it less than me, they really don't know it! But they can beat me only because they have a WAY WAY WAY better car so they're able to go faster from sloppy corner to sloppy corner knocking other cars off the track every chance they get. it's silly.
One race online it was funny, the guy would knock me off the track even though I was trying to allow him to pass... so I'd get a penalty & drop behind, only to catch up to him again & again when he wiped out at the next tricky corner.
I'm not sure I'd feel any ego boost by winning by driving a fast car from one sloppy corner to the next against people driving lower grade cars well... I think I'd be embarrassed to beat someone the way that guy did.
but maybe I'm the crazy one. Maybe it's normal to buy a game with thousands of cars to choose from just to get one or 2 massive cars to beat newbies online driving lesser cars.
As far as I can see the only winning that would count PERSONALLY (ie: displaying driving skill) would be a one make race with a PP limit.
Otherwise, we're just talking about showing off how many hours we've grinded for credits to buy the leet ride. (or cheated for credits for that matter)