I agree with you about the scores being unrealistic, but I have a friend who caddies on the European and US PGA tour and he says the courses on here, especially the greens are so realistic it's as close to the real thing you will ever get.
The reason why the top pro's hardly ever shoot below 60 is because they don't have knowledge of wind speed and direction, a putting grid that tells them distance from the pin and where to aim. They also don't have a meter that tells them exactly how hard to hit the ball.
I'm pretty sure if they had all this help, you would see scores below 60 every week.
P.S
I.ve broken 65 many, many times playing real golf . )