I can generally agree with that statement, but there are qualities of games (as there are in all art) which are so subjective, that they cannot be quantified. There's also the matter of personal tastes, which extend into game graphics and music, such as the musical example from a page back (Deforestation, I believe it was).
As such, saying something as vacuous as "This is better than this", at times, is not a fact but rather a personal opinion, no matter how loud and bombastic your post about it may be. There's nothing wrong, nor does it waste a lot of time, to say "I find this better than this" or "I think I'm more fond of this" rather than "This is absolute shit in comparison to this clearly superior thing".
It's really the presentation.
One makes you come off as a practical sensible member of the forum, and the other one will make you come off as an ass.
Also, one of those will get you banned eventually.