How does FF14 compare to WoW? (And other MMOs)

[ItMe]

That's really the thing about raiding though. As a concept, it's multiplayer only. The argument that "It's not a good game concept because it's not seen in single player games" is kinda like saying that "PVP isn't a good game concept because it's not in a single player game". PVP will need players for the player to fight with, Raiding(Cooperative PVE) will need players to raid with. That's how it is.

Not necessarily.
The term is so vague that it can easily encompass single player games where you raid with AI allies.
As long as you're part of a group (human or otherwise) the term sticks.

Disregarding a game concept just because it doesn't work in a single player setting is just plain silly.

You're right... to a point.
In this context Ihowever, I think it's a fair statement.
I think you hit the nail on the head with your comments about raiding being about socializing and cooperative play. But that raises the question if these things are fun because they're fun, or because you're with your friends.
If you strip away the socializing, raiding seems to be a hollow enough experience that it can't carry a game. So basing a game AROUND raiding (when it's strongest point is the socializing that happens around and outside the game)... might not be the best idea.