God I hope Dwarf Therapist never becomes the default interface for the game. I completely agree with Toady on his dislike for a game about micromanaging every single dwarf in a spreadsheet.
I mean, yeah, it's popular enough to include as an option deeply buried in an advanced tools window somewhere, but as default, you've just killed the game.
Therapist as an alternative to the current system seems nice, because the current system is so poor, but it's really not the only option. And, "fans like it, therefore Toady must make the game according to their whims" has never been the way Dwarf Fortress had been developed. We celebrate it because it's an independent project, not because it's yet another game-by-committee developed by some massive studio.
For the most part, I find DT to actually
add to the time it takes to complete tasks. I prefer just to burrow all migrants and manually check their skills. If Dwarf Fortress, by default, allowed you to bring up a list of most suitable dorfs for a task, like a list of mechanics for when you want to make mechanisms or a list of axe wielders when you have an open position in the militia, I don't think I'd use it at all.