I think a lot of the gripes between solo and group players is that some people who absolutely abhor solo play in an MMO think that we want the entire thing solo. This couldn't be further from the truth. Our main gripe is not wanting group play for everything.
Levelling and storyline should have solo options, maybe with some storyline like bigger fights catering to light party since it doesn't make sense to be able to push through every important part of gameplay (lore-wise) on your own.
Trying to find an 8-man group for stuff like the Castrum Novum fight was cumbersome if everyone you knew had already done it, same for the fight against Nael Van Darnus (Not counting Rivenroad [Hard]).
My work schedule had gotten the better of me and I was reduced to shouting in Ul'dah for days on end until when I offered a substantial cash reward did I get an answer. (However the guy that did take me under his wing, didn't take my money and instead offered me a place in his linkshell where I remained quite happily til the end of 1.0, so props to you, Yowyow!)
For things like raids and whatnot that offer the top of the line r/ex gear, I agree that this should remain as group play. You shouldn't be able to obtain absolutely everything in game on your own. At the same time I'd like to see some light party options for this as well for some of the lesser-end raid gear but keep the omg-foam-at-the-mouth-awesome stuff for 8man.
As a tl;dr: We're not asking for the entire game to be solo, maybe some solo levelling and storyline options. Levelling efficiency should go up with your group size but solo should still be viable. Storyline aspects of things would rock as a mixture of solo/light party, Raids between light party and 8man then for the uber stuff push for 8man~