FWIW, my local Walgreens does not carry any hunting or shooting magazines on their magazine racks either. The whole chain seems to have a policy of disliking civilian gun ownership, hunting, civilian use of firearms for sporting purposes, etc.
Those two things could be completely unrelated. I've noticed that some Barnes & Noble locations carry gun magazines, while others don't.
Shelf space is limited, and if a given product doesn't sell, retailers don't want it taking up shelf space.
If I were to boycott every establishment that doesn't allow their employees to carry, or who simply don't trumpet their support for the 2nd Amendment from the PA system, I'd rapidly run out of places to do business.