I don't think the game should have a DPS meter, but mostly because of how the game is balanced and how easy it is to misinterpret raw DPS numbers. I much prefer the current system when it comes to assessing hard DPS numbers.
However, I think the game is currently a bit unfair to DPS. If I make big mistakes tanking or healing, it's pretty obvious I did something wrong, but making DPS mistakes are much less obvious. If a DPS is pulling half of what they should be pulling, how do they even know to reassess their gear/rotation?
I do hope SE implements something to give DPS a better idea of their performance, even if it isn't a raw DPS comparison.
