The WoW vanilla devs definitely painted themselves into the corner with Mage PvE.

Before implementation the concept seems OK; ou have a nuke with a dot (fireball), an even bigger nuke with a bigger dot (pyro), a big long channeled nuke (AM), a control nuke for less damage (frostbolt), a smaller quicker efficient nuke with a debuff (scorch) ... and you have to alternate between them depending on the situation. Fire and Arcane can be the PvE damage rotations, Frost can be the control spec in PvP!'

Except talents made one nuke significantly better than the rest in all situations

... and the secondary effects were relatively trivial compared to the pure damage, making it just different flavors of the same thing

... and that supposed 'PvP spec' turns out to be the only viable spec for the beginning of endgame, because they recklessly made the first few big raid dungeons essentially immune to fire damage

... and the encounters turned out to be 99% tank and spank, making any variation in spell choice completely irrelevant

It's like if you're trying to build a piece of furniture but got the first step wrong and didn't realize it until you got to the last step ... you can either tear it all apart and start over, or admit defeat and settle on using it as is, dysfunctional and disfigured.