I have been kicked once for inefficient heals, we were at the end, and I was healing fine no deaths no nothing. The tank initiated it and the dps blindly agreed. I know because the two dps were from my server and when we met they told me they just did it without thought, they apologized and said they eventually voted abandon because no healers ever made it. It wasn't too bad, the tank just thought I sucked, and it made me upset but I got over it. I befriended the dps and they said my healing was just slow so I worked on it. Yeah it sucked being kicked but hey I wasn't doing my job, so in the end it was my fault. The kick system can backfire but really its not terrible.