I think what Square was missing in FFVI and FFVIII was the "feature filter." The feature filter is the guy who says "uh... no" when someone suggests a new feature that won't work very well. "Hey, how about we completely eliminate items from the game?" "Uh... no." "Hey, how about we allow all 14 characters (OK, except Umaro) to learn every magic spell in the game for exactly the same amount of effort?" You get the point. :)
I agree that FFVI's broken gameplay doesn't keep you from playing it, at least in the beginning. But when you get to a weak point in the plot, good gameplay will keep you going until it gets good again. The lousy gameplay is one of the reasons I rarely come back to FFVI, and even more rarely finish it if I do start a new game. It definitely makes it less of a good game for me than IV or V.
I'm not trying to convince anyone not to like VI, it just isn't for me. I get what they were trying to do with the character development, it just didn't reach me.
I think I'm going to dislike FFVII for having only three characters in your party at a time, and no battle rows. It worked in Chrono Trigger, but dammit, I want more strategy!
