...the reason we were dying so much was because the person that was supposed to be healing was dps spec.
This really is the fault of the guy that is supposed to be filling the healer role and is DPS specced wouldn't you say? We kicked a guy from a group the other day not only because of that, but also because he was a pompous windbag that was rude when we asked him what's up?
Until Dual specs you should not be able to choose 2 different roles in the group finder.
Agreed but people now have the ability to field respec. I am guessing this why that option exists - for people who would use the field respec to fit into whichever role they got.