As far as caster DPS goes, it's hard to gripe about hurting for choices.
Fire Mage is great and the other specs are okay.
Elemental Shaman looks amazing, feels good, apparently is so-so in Legion but it usually takes a patch or two for them to shine.
Shadow Priest is really good, it's like a correctly executed version of the old Metamorphosis.
Balance Druid is simple and predictable, no procs and only one major cooldown.
Only the Warlock specs really seem to be causing a lot of grief. They are still ridiculously survivable, provide indispensable utility, and solo content as well as tank classes, but apparently that's not fun enough.