Personal opinion, YMMV...
Can't say as I see the appeal. Far more power and recoil than needed for even elk at any reasonable distance. Clearly unnecessary for anything smaller.
Doesn't fill a need for the VAST majority of shooters, who can do anything they'd ever want to do with a 30-06, 270, .308, 7mm-08, 25-06, 243... or myriad other choices with considerably less recoil.
Beyond 200 yards or so, a 30-06 has more energy and under 200 yards the 338 has more energy than will ever be needed for most applications.
I'm glad you like it but I don't see any reason why it will or "should be more popular".
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.