Legendary games designer Shigeru Miyamoto says that Wii U video game development actually requires twice the human resources than before. Miyamoto explained that the teams have struggled to adapt to the HD era, and a result a number of software titles were delayed. However, Miyamoto says that Nintendo is almost out of this phase and are creating an easier development approach.

“When it comes to the scale of software development, Wii U with HD graphics requires about twice the human resources than before. Please allow me to explain that we may have underestimated the scale of this change and as a result, the overall software development took more time than originally anticipated just as we tried to polish the software at the completion phase of development. However, we are almost out of this phase, and we are also trying to create something unique utilizing an easier development approach called “Nintendo Web Framework.”


Source:http://mynintendonews.com/2013/07/05/wii-u-game-development-requires-twice-the-human-resources-than-before/

No excuse, they abandoned the Wii, so they had extra time to work on Wii U. Yes, I know a lot of resources were sapped trying to fix 3DS, but still, a certain amount of time should have been put into the Wii U. If they truly thought game dev time would be the same for the Wii U, then they are idiots.

Super WiiU will require 4 times the amount of human resources. What will they do then?

It's kinda weird because basically everyone else in the industry has already had these growing pains of delays and finding out how much more effort HD development can take, and now Nintendo is finding out the same thing years later. You'd think one of them would've read a forum post about the SD to HD transition and seen this coming a bit better.

No wonder third parties have been so reluctant to support it. Where are they going to find an extra two people?

More admitting that they put out a product without actually thinking ahead.

Love Nintendo but seriously surprised this sort of stuff is going by without a sacrificial lamb being offered up as to why they are failing in being ready for their own new hardware.

Nowhere did they say that they thought that.  They most likely knew it required more work, but as it clearly says, did not expect to use twice as much as they did with the Wii.  

Also, they aren't making an "excuse" the way you're using the word (because even if they said 'we are stupid we couldn't do it', that would be called an excuse as well), they are simply explaining that they made a mistake.

 Reading about it is very different than going hands on and doing it.

It's not a conspiracy that Nintendo put out the Wii U without actually putting any thinking into the process. And this just continues to confirm the point.

At least they seem to be getting out of that phase, like Miyamoto said, with the release of one published/developed Nintendo game every month from August onward.

all companies have to adapt to HD sooner or later.