I usually feel that the negatives outway the positives on the "classic" FF games. Really the only ones I like are 1 and 9.
I also kind of like 10, but it does have some massive flaws that bring down the enjoyment level for me.
12, apart from the plot, is fantastic. I don't care what anyone says.
Anyway, as a response to the question of why we forgive older games for having flaws, but not newer ones, I'd say that flaws don't make or break a game. My favorite games actually tend to have massive flaws, but if the pros outway those then it just doesn't matter. I don't play many modern games but I imagine my response would be the same regardless of when the game was made.
Of course if game developers continue to have the same flaws in their games over and over than it makes sense to criminalize the newer games while still respecting the old ones; ie. they didn't know any better back then but they do now so said flaws should have been fixed.