Everyone will likely have a different opinion based on what they normally play, but in terms of quantifiable performance, I would say that DPS take much more criticism because their performance is rated on a statistic that does not always correlate to the final outcome.
If the tank keeps the bosses attention and we kill the boss, they did their job.
If the healers keep their targets alive and we kill the boss, they did their job.
If the DPS doesn't have (insert # here that should be easily achieved by your class, noob), and we kill the boss, they are a drain and will be talked about in officer chat.