No, even in high survivability environments like a static Voidstar (0-0), where death is rare, the top melee dps will score about 50% greater damage than a Merc dps. Sorc/Sage dps is about 25% higher. Even operative dps is about 10% higher. Merc dps damage output sucks at the top skill levels. And it has the lowest survivability. And the lowest utility.
Where are you getting these percentages from? Don't just pull numbers out of your bunghole and treat them as if they were something reliable. I can out dps anybody on my merc. Ive put up 800k in VS and nobody else even broke 500k. You are right though about the low survivability and utility. The only time my damage suffers is when I get a guy or two from the oth!er team that focuses me every time, cuz we are pretty easy to kill. But, if they leave me a small window of time in a big group fight, many will suffer and many will die.