I'm always surprised when I see the installment base of generations and compare it to software sales. If this generation happens to lose a chunk of the more casual or Wii audience wouldn't that have little affect on pubs though? It seems like the hardcore/core are the ones that actually buy the games each month and it seems like they will at least be retained or replaced gen to gen. If you're losing people that only bought Wii sports because they're playing candy crush now it shouldn't affect the core game publishers I wouldn't think. I don't think total consoles sold tell the whole tale. Have software sales (not sure without digital) been worse from previous gens?
I do feel dedicated handheld is dying that said though.
The Wii sold 900M pieces of software, but I do agree that the major publishers never really invested significantly in the Wii.
The real issue is growth: because development costs continue to escalate, the publishers need growth to sustain the track they've been on for decades. The problem, then, is that this Wii audience (which is now a mobile/casual/browser/social audience) is where all the growth is.
So I agree that the big publishers have not really invested all that heavily in to what we refer to as the "casual audience," but that is in itself a big problem. They need growth, and there missing out on all of it right now, which is what has allowed companies like King and GungHo and Supercell to rise so rapidly and astronomically; they're swimming in the growth area of gaming with little competition from the established players in the gaming market.