Can someone give me an in-depth explanation why Summoner is arguably the worst DPS?

[scarebearz]

And yet, world second group. We blaming the content not being tuned or what?

A Dragoon who is good at their class could clear T9 fast, so what?

A Good SMN in a top-end team could have been world first for T13, it would not change a thing.

The important part for those teams, would have been learning the mechanics first, for players of that level, the dps would not be a major issue once they knew the fight.