I don't know how much racing you do, but as far as I've seen, racers do tow their race cars to the track. They rent or own tow trailers and transporters.
Race cars are usually heavily modified and aren't street legal, and the drivers don't want them dinged up on the way to the track, and if they fail while racing they need a way to get it back home.
If you're racing a street-legal car on a track... it's unlikely to be very good at racing, compared to all the other cars there that are stripped to bare minimum.
Perhaps you're thinking of a demographic who can't even afford a second car but like the idea of racing anyway, so they break all laws and race the one car do they have, on public streets without permission, which is strongly disregarding others' preferences for remaining alive, uncrippled, and their vehicles and street furniture remaining unscathed.
You are talking about serious people not street racers. This is not the demographic who's going down my street five nights a week at a hundred mph in clapped out mitsubishi.
It's a spectrum. If you're really serious you buy a trailer and all that. But people do bring their street legal cars to the track all the time. Either because they go to the track as an occasional hobby or they don't have the money to shell out for a second car just for racing (i.e. they're young).
Race cars are usually heavily modified and aren't street legal, and the drivers don't want them dinged up on the way to the track, and if they fail while racing they need a way to get it back home.
If you're racing a street-legal car on a track... it's unlikely to be very good at racing, compared to all the other cars there that are stripped to bare minimum.
Perhaps you're thinking of a demographic who can't even afford a second car but like the idea of racing anyway, so they break all laws and race the one car do they have, on public streets without permission, which is strongly disregarding others' preferences for remaining alive, uncrippled, and their vehicles and street furniture remaining unscathed.