I meant that I disagree. These are things commonly said in absolute terms but they are not really true because the situations are complex. They did focus on more casual because it was major market opportunity for them, but there were still core games on the platform, and many of them were console sellers such as Monster Hunter Tri. They did not completely disregard core. It's just in comparison it looks like they did because the markets enabled them to sell so much more on casual appeal. Neither PS4 or Xbox One are close to the units Wii sold. And now markets have changed and gamers have even more to choose from. Because Playstation and Xbox existed it forced Nintendo to be more strategic. Playstation and Xbox both had strong ability to pull certain kinds of gamers with their core console selling IPs which strongly appeal to certain kinds of core gamers - and a big part of this that was and still is a problem for Nintendo is that developers who want to make certain kinds of games choose those other platforms to release on because the audience already exists for those platforms largely thanks to the super core console exclusives. If Nintendo had done the same strategy Sony and Microsoft did with Wii they would not have had the same success.
These are just memorable ones. There are more. Compare these titles that were published with past generation titles. They are not less core.
Also something Nintendo has that others doesn't have is much stronger mobile platform that does ship many more core games.
Their bigger core IPs for Wii U afaik are not released yet. They will be console sellers because of the IPs they are based on. Wii U has sold 10m without as big of heavy hitters, without as market strong core console sellers like Destiny or Bloodborne. I would bet when their bigger core hitters come out their console sales numbers will be higher.