Because the way kunos designed the whole on line features is simply amateur, unpractical, unattractive, you name it. The word spread fast and i can tell you that A LOT of my friends refrained from buying it because of that.
Another stupidity is the freaking region lock! Apparently, the European community is huge but out of reach for us north americans that are locked in one and only server.
All of this is tremendously sad because the game's drivability is by far better than anything else I know in the console universe.
