I think there should be some forum lore behind having Weapon Pool Skills called exactly that, considering that in-game name for them would be Techniques.
I wonder about those ancient times somebody came up with an idea to call it a WPS for the first time, instead of “tech” or something.
For the record, I have no issue with them being called WPS, it’s just not obvious and I think for a new player it would make more sense to refer to them as techniques.
It may date to the remnants of an era that gave us “proc”, as they are things that go into a “pool” of “skills” that you put skill points into which only are usable with default “weapon” attacks. Which is to say, very much named after the implementation of the concept.
“because it’s written in the game files” 
anyway this was what i noticed sometime ago, DARs are called weapon pools in the skill templates
so it might just be an extension of that already existing term they had implemented prior
Augments basic attacks with charges, namely $5.99 or $3.99 with Season Pass.
