Nah, it's just because GTA 3 games themselves were overrated... San Andreas averaged a 9.5... and while it has a bunch of minor flaws... GTA4 has many less flaws then GTA3.
GTA3 never got docked for it's graphics and polish flaws either... because people just expect their to be issues all over the place in sandbox games. I mean from all accounts compared to all the issues of GTA3...
GTA4 is getting a free pass on some issues because all the GTA3 games got passes on the exact same issues.








