I doubt today games will be the retro games of tomorrow. I can't see anyone remebering how good it was to play Quake 1...
And even being subjective, no one can argue that there are factors that DOES make a game (or music or movie or whatever) good or bad. You know a movie like Men in Black II is bad because (SPOILER) it's just trying to make money from its name, it reuses lots of jokes from the prequel, it has holes in the script, the plot is nearly identical to the 1st one, the direction doesn't work in many points of the movie.... do I need to go on?
Someone may even say "I liked MIB II", but this doesn't stop it being a bad movie.