Maybe a badging issue due to all the name changes?
Or maybe the kind of person that will drive a 15 year old car doesn't like compact cars?
Integra (2001 was last US production year) and RSX are both inline-4 with relatively agressive compression ratios. Anecdotally, an owner who purchased new as a daily driver with no intent on abusing the vehicle is liable to start encountering appreciable maintenance costs at 120,000+ miles. More often than not, these vehicles find a 2nd (or 3rd+) life on the used market. 10% ethanol gas didn't make reliability any better either.
I see a lot of 15 year old cars driving around in the UK (age of car is easy to gauge here, as it's encoded in the number plate) - I expect most will have changed hands at least once.
The Integra was a great car though ...and great name!