I don't see a problem with speed-running. As people have proposed countless times through this entire thread: Communicate. You don't need to change the mechanics in anything, you don't need to 'outlaw' speed-running.

I'm a very casual player and like to play at my own pace (which is VERY slow...), but when you are partying with others--especially strangers--you want to be respectful of their time. Grinding end-game is a very tedious chore.

I just dunno what all the hoop-la is about. Some people have a preference for it, some don't. It boils down to just about anything in life. It is -YOUR- responsibility, as a player, to cope with it. Don't put the burden on Square Enix. They've enough on their plate as it is dealing with ACTUAL problems like programming bugs/issues and adding planned patch material, and someday I'm sure they will increase the level cap or add classes/jobs.