Lukas Mathis nails it down:
“If the «post-PC era» truly had such a devastating effect on the console market that the Wii’s sales just deflated after 2008, it’s unlikely that the same effect would not also be seen in the PS3’s and Xbox 360’s sales. But Asymco’s huge 2008 peak mainly exists because the Wii peaked in 2008, and because back then, it outsold its competitors by large margin.
In other words, many consoles show Wii-like sales curves – but not the Wii’s direct competitors, the PS3 and the Xbox 360. If the Wii’s sales peak in 2008 was indeed mainly caused by the «post-PC era», you’d expect the Wii’s direct competitors to be similarly affected. They’re not.”
I remember thinking in 1998, with Age of Empires, that I would abandon consoles for immersive PC-only gaming, but here I am clinging to a 3DS and a Wii U. My PC became a distraction conduit for email, ICQ, AIM…well let’s just stop there.
But I think my anecdote shows why dedicated consoles can still work, at least for the tasteful gamer. For the dedicated gaming market to truly feel the pain, smartphones would need much better battery life than they currently have. Their very strengths – being Swiss Army knives with tons of radios – also means that they cannot muster the battery life (or rather, the singularity of vision and focus) to support the longer-form gaming experiences unique to consoles, especially the DS line.