Dark Archangel (Dark Ascensions predecessor) never had a cast time in Cataclysm.
Voidform has always had a cast time with Void Eruption doing damage aside from the PvP only Void Origin when it did exist.
Mind Spike was instant cast (Procs) for the entirely of MoP and WoD alongside also having Mind Flay.
Halo, Cascade and Divine Star were all instant Cast in MoP and WoD.
Also, they made a mistake creating Surge of Insanity in merging 2 completely different spells together.
They should be their own talents with other talents that synergies with a specific spell so they can become more interesting.
So if we look back and compare pre and post Voidform, you can clearly see all the issues we have today were not issues pre Voidform and have always been issues post Voidform.
So what is really dragging down Shadow? It sure is not Dark Ascension and it sure is not Mind Spike as the records speak for themselves.
So I would argue its not an issue trying to cater to 2 different play styles, it’s an issue because specifically and solely the way Voidform currently works creating a cascade of issues like wretches being thrown all around the gears that make shadow work and it gets clogged up and seizes and breaks down.
It has always been Voidform as the centerpiece of Shadows problems.
We need to redesign Voidform and break up/separate Void Eruption and Void Bolt into their own separate and respective spells. That will go a long way in allowing the rest of the spec to breath and heal and actually evolve instead of this fake evolve that has left Shadow remaining stagnate or when compared to other classes it seems like it’s more so regressing in terms of design philosophy.
Also I would / could argue that there could also be a slight chance that Shadow having that slight extra bit of mobility caused by Void Bolt could also be the deciding factor as to why Priest as a whole in the class tree doesn’t have better mobility/Displacement capability.
It might not be related, but can we really rule out that possibility at this point?
So I can start to conclude that Voidform not only drags Shadow down but it may also be seeping into Holy and Discipline and affecting them negatively as well.
It’s a far reaching stretch, I know. But something in my bones just tells me somehow it doesn’t seem to farfetched.