No, that's not why.
The reason why is because the hardware is 10 years old, and been out for 8.
Liberty City was just as few people... on consoles.
The only living, breathing GTA experience, it doesn't exist on 360 or ps3. They are ghost town games compared to the version you can set how many peds and traffic you want with an "options menu"
For those who don't know:
An "Options Menu" is where you set up how you would like the game to look. You trade off performance for visuals, and depending on the power of the machine you're running the game on, depends how much you get hit for using the "full look" of the game the developer created.
It's not as convenient as putting a disc in and playing, but it certainly is a higher value.
Sound like some kind of elitist post? Don't hate, and get off my scrotum, because the facts need to be said, and I am NOT sitting back and watching people "assume" and "make sh*t up" just to "explain away" the utter FACT that the machines just are not capable of populating the area - period - the machines cannot support the "max traffic/ped density"
It has nothing to do with game design or lore or "on purpose" and everything to do with HARDWARE LIMITATIONS.
Anyone who saw that "cops:LS" vid, you saw some serious traffic - that will be like that on PC's that can handle it (but not on PC's that cant, nor on consoles)