Let's not go to the extremes of "there is currently no reason to take a mch into any group". There's currently little that we're absolutely incapable of doing at the moment, and while we need some retuning, we're far from unviable. I personally haven't had much issue keeping up with other DPS in the party (SAM and MNK being notable, obvious exceptions), or catching back up if I accidentally overheat, but I can only speak for myself there.

The raids aren't out yet, thus SE is still in a "wait and see" stance on things. In time, they'll see what needs to be seen and hopefully fix what needs to be fixed.