I understand the design complaints--the gameplay won't resonate with anyone wanting a strategy game of any depth--but saying they did poorly is pretty hyperbolic. It obviously struck a chord with some segments as I do still see people playing in dense areas (and at the local game stores).
I also think looking into Niantic's past work or Pokemon Company's past partnerships would've revealed this game couldn't possibly have the mechanics of the core Pokemon line, but I do understand that the marketing and messaging was very vague.