Just like every other sim out there, if you give 100 people the sim with the same controls, you'll get a split of "I love it, it's the bestest ever", "it's okay, but not much better, if at all, over previous sims/versions" and "there is something wrong here".
I don't believe all of it is trolling or fanboyism - I like to think that I'm honest about my feelings of the various sims out there (obviously haven't tried GT5, as I don't own a PS3) from LFS, iRacing, nKP, rFactor etc etc. Each one has strengths over the others (rFactor's being the brake squeal), but at the end of the day it's what feels right to each other.
I've driven racing cars, and I base my opinions on how games feel in comparison. But other race car drivers come to different conclusions of what is realistic. I suppose that how each of us 'compensates' for the lack of actually being in a car is the biggest differential - the cues we use in a game are, obviously, quite different to real life in that respect.
I rely massively on FFB, which is one of the reasons I don't rate iRacing and rFactor on. But other people - perhaps who rely on FFB less, might think they have the best FFB? Maybe if you rely on it even more it that I do it's also useful. Graphics mean nothing to me as a player. Sound is important - I'm generally quicker (relative to the majority of players) in sims with simulated sound rather than sampled sounds.
I'm going to think about this some more...