playing with other class/specc combo from the ones expected to raid is playing WOW in hard mode.
none of the so called "hardcore" or "elitists" players wants to play this game in hard mode because in the end they only feel happy when looting some boss.
and since the easy mode is decided for ten years, expect a lot of opposition and much less chances of going to raid with other specc, different from the ones they expect you to.
they don't care if you have fun playing this game from another view point, if its fun for them to heal as a druid IT HAS TO BE fun for you too.
if not, leave the game and let them get their loot. you're a stone in their path.
(did MC as elemental in the retail version of vanilla, so its possible if you find the right guild with the right mindset, otherwise the game will only be fun when you did it all and then... well, no more fun for you.)
good luck and hope you have fun. (that's what counts even if you're a "hardcore" or "elitist")