Its not that I dont like it cuz I do. But why is it so popular?

perfection? attention to detail?

just cuzzzz

or....OR....maybe it's the same reason why other popular games are so popular...

from wiki:
Gran Turismo (GT) is a hugely successful and critically acclaimed series of racing video games produced for the Sony PlayStation, PlayStation 2, PlayStation Portable and PlayStation 3 gaming systems. All of the games, for their time, exhibited superior detail in simulating the appearance and performance of a large selection of vehicles, nearly all of which are licensed reproductions of real-world automobiles

because its the best racing sim on the market, by a furlong.

The idea of racing in cars, that almost none of us can afford, against other people or the NPC and the feeling of proving how awesome our driving skills are through analog sticks/plastic driving wheel is something of a guilty pleasure for many people....

And don't think I am being overly critical of GT5 b/c I don't like the game...even though I actually don't....

My guilty pleasure is to pretend I have a sword and I am slashing and vanquishing monsters in the hopes of saving an entire kingdom from an evil dark magician.

Gran Turismo is so popular because it was the first game console game to give you the ability to drive hundreds of real life cars in simulation style racing game. It was the first of its kind and has very loyal fanbase because it. Its popularity lead several Japanese manufacturers to bring over some of their more popular Japanese only sport cars. The Evo and WRX would have most likely never hit the US without Gran Turismo's popularity. Car guys that didn't care for video games, picked up Playstations to give their favorite cars a virtual test drive.

I really don't know why. I think simulation racers are easily the most boring things ever.

Cause by far its the best in its genre.