Shouldn't that be "stop focusing on casual games"? Which is of itself pretty silly advice for a busness (sp?), "please cut out a massive market so that you can focus on pleasing me and my other gaming friends".
Overall, if you don't like casual games don't buy them. And Nintendo is a games company which takes its time on games to make them as good as possible (well, most of the time), so Iwould advise you be patient and allow Nintendo to work their magic on their next franchise. In the meantime, many 3rd parties' games are very much playable. Capcom usually does very good games. Sega is hit and miss, but as a publisher, they're gathering steam.