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

[Xisin]

The gcd is still there regardless of the astral/umbral influence it just affects cast time. This effectively gives blms some time to move and to finish a cast as its benefits. That said, it's not quite what spell speed gives. Also the potency of fire 3 and blizz 3 are at 70% since you are casting in opposite influence. The selene bit pretty much solidifies the evidence that spell speed is causing this balance issue. If summoners got the same value that blms did from spell speed (as we get similar returns from det/crit) then it'd be A-OK fine.

Even more concerning is that a summoner passive gives a spell speed boost (lolreally?) the passive happens occasionally on pet crit. Summoners do not need a potency increase leading into 3.0. too many things can change. I'd honestly just rather them change how spell speed affects summoners or just give smns a set of gear to themselves. It actually makes more sense to separate blm and smn than it does to separate drg and monk. The only reason I can see drg is separate is the innate defense value of drg gear.

Also the parses i mentioned were both 3 min duration (thats the blm in me, as it really only matter until Raging strikes resets.)