When I queue as tank, I don't usually get healers who instaquit like tanks will. Fairly often I get healers who refuse to dps, and those dungeons take longer for no reason. I don't kick for just that reason, though. Some people are bad. In duty finder, I work with who I get, as long as they're trying and have a positive attitude.

If you were eating your dinner and barely playing on purpose, then you deserved to be kicked. Three other people stuck with you don't know anything about you. They don't know you've built up so much karma by helping out people (and that you feel entitled to cash in your karma at the expense of three strangers). All they see is a healer who is barely doing anything. They don't need to wait on you. Eat your dinner first, then queue.

I don't agree with them kicking you, since they didn't know whether you were just bad, but knowing your reason for why you were playing poorly, you deserved it. Next time please be more considerate.