Failure of core Wii games has more to do with lack of marketing IMO.
If I start seeing 3rd parties spend the same amount on advertising Wii hardcore games as they do 360/PS3 games or Wii casual games..and they still fail..then I'd say you have a point.
I have yet to see one tv ad for House of the Dead Overkill or Deadly Creatures..so I don't expect either to do well.







