Wut? Of course they have the ability. Or did you mean 'Can'?
Also anyone calling for Iwata's head simply doesn't understand the world of big, publicly traded corporations. It would be enormously damaging to step down right now.
Let's not forget Iwata is responsible for dragging Nintendo back into relevancy after the GC dark days. He might not have been responsible for the DS but he is responsible for steering that ship into enomrmous profits. He is responsible for Wii and 3DS l, which have made Nintendo buckets if money.
You don't sack this guy after one failed concept. It's a very Western thing to immediately fire everyone as soon as one thing goes awry, and it usually doesn't lead to good things. It would be irresponsible at this point to disrupt the company like that and fire somebody who has brought the company success on the whole. I'm not sticking up for the guy because I like him or because I'm defending WiiU - I dont particular like him and WiiU has been a failure of Iwata's doing - I'm just trying to be logical.
In short, he probably has another year or so of good will to get things right.
Edit: and FWIW, I would like to see him step down and for some fresh ideas at the top. But then I'm not a shareholder