My own group are full FC group, we arent hardcore who race to be first clear
but then if I am doing it with pug or random players, I would want as much DPS as possible, more DPS->less fight time->less mechanic->less chance anyone make mistake->less chance of a wipe.
I have seen some group exclude specific job, i have see multiple group specifically "No RDM" in first week
Meta will always be there, is how much the gap between the top job and lower one, big enough to exclude lowest job or small enough most players wont even care