The way LFR is set up at the moment is just ... sub optimal.
First of all you have 5 different LFR, but you can't queue random (in this case meaning those which you haven't killed ALL bosses in). So you don't have a combined player pool to get players from, which would shorten queues.
Secondly, people are discouraged from using their dual spec, because they will only get rewards for whatever role you get chosen as.
And thirdly, most guilds are 10 man, meaning players usually come as 20% tanks, 30% healers and 50% DPS (DPS usually is higher, because of the more casual nature of that role), whereas LFR demands another role distribution (8% tanks, 24% healers and 68% DPS).
With the second and third reason are being very closely related.
Indeed i have to gear ofspec for raids i ahve
Forgot about that one. I'm main tank so I have never done anything else. However our offtank does switch to DPS during four kings, as well as a few healers able to do the same.
So I guess I can count myself lucky as to not having to worry about another spec.