Heyo! I have never actually had a problem with healing either normals or heroics (I'm Paladin<3). Sure, they're hard and you actually have to make an effort compared to neverending mana spamhealing the tank in WLK.
But now I've had enough. Every wipe it's my fault. "You didn't heal the tank!". Well no shit, the DPS is doing 5k-6k each (usually i've seen DPS do atleast 8k) and the boss took ages to get down. Went out of mana and still kept up the tank and party pretty good from 30%-5% health before wipe.
On that fight I pushed out 9k HPS (Usually 8k~ish with some mana over in heroic bosses) because I had to spam heal the DPS since they don't understand "Do not stay in fire!".
The boss fight was "High Prophet Barim". Didn't even had a problem with him first time I did the instance with blue/green gear, now I got ilvl 346.
They kicked me after arguing how I failed as a healer and should learn 2 play. Are people really that thick minded? Don't they know by now that healing actually isn't easy and they have to make en effort themselfs as tanks and DPS.
Before you tell me to do guildruns, we're a small guild with 6-7 IRLS and we're not always online at the same time. I have a 8 months old son to take care of aswell. Almost everyone have enough ilvl for heroics now though, so will be doing heroics with guild only after christmass.
So, I beg you random and think headed people. The problem can be both DPS and Tank, not just healers.