Pokemon Go is magnitudes larger than Ingress, their previous project, even though it's been plagued with more issues than Ingress and is arguably not as fully featured.

The difference?

Pokemon, which Nintendo owns.

If I was an investor, I'd view the potential for licensing the Nintendo IP (something Nintendo has been extremely reluctant to do in the past) as a huge potential growth vector for a struggling market segment (consoles, specifically Nintendo-made ones.)