No, what's unfair is to write off a game as a 'classic' and consider it immune to criticism. Only the people who grew up with these games can hold opinions on them? Gee, that doesn't sound biased at all.
I'm 100% aware of the historical value of a lot of old, revolutionary titles, but reviews have nothing to do with historical value. If a game took big steps forward for the genre then put it in whatever hall of fame you think it belongs, but as a game it will always be open to criticism as long as people are still playing it. I don't enjoy games based on the varying eras of the gaming industry they came from, I enjoy them as they play in front of me.
Agreed. For example, I didn't play any SNES RPGs for the first time until the PS2 generation. When I did, I found that there are those "classics" that I enjoyed and hold up very well to this day (Chrono Trigger, FFVI, Super Mario RPG), there are others that I didn't like as much and felt that they're more "of their time" (FFIV, Earthbound, Secret of Mana), and some in the grey areas inbetween (Harvest Moon).
I feel that there are a lot of gamers who are fueled by childhood nostalgia, and therefore, the games they played back then are, more often than not, Classics. Also remember that a lot of times, kids were restricted to what they got as presents, rentals, and what they could scrimp and save for. With those restrictions, you take what you can get, and stood by what you could get, which only strengthens said nostalgia.
One major problem with retro reviews, though, is that a lot of times, they're colored by this nostalgia. A truly good reviewer wouldn't let this happen, and would take the game at face value. Then again, one should be picky with which reviewers they trust overall.