Yeah I'm sure every role gets called out form time to time, but I think it's just easier to notice bad performance from a tank since they're the one kind of setting the pace, usually.
As someone who plays DPS almost exclusively I find it harder to judge the contributions of the tank or healer in my party while I'm busy beating everything up. Sure there are ways to tell how other players are performing regardless of role, but if the tank or healer messes something up then it tends to have an immediate and obvious effect on the run. Bad DPS? Things die more slowly, which you may not notice right away.