I am for jump, and my personal opinion is that I don't mind if people do it all day every day. I do not predict there will be many people who actually spam it anyway. Maybe a few, but this is a Final Fantasy game with a strong FF base, I don't think we will have a bunch of jumpers around. For a few people, jumping will be a very freeing evolution with XIV, I don't think limiting jumping would help sell the game.
On a side note I am looking forward to experiencing another dimension of game play "up".