And, on which platform do you think those apps were created? On an full Apple computer with Mac OSX, most likely.
Try to program on the iPad. (i) you need a proper keyboard, (ii) you need a proper dev environment, and (iii) interpreters are forbidden and you are not root anyway.
Try to do anything on the iPad. You need an App. And since you can't write one yourself (at least not on the iPad), you have do download one that passes through Apples moral filter (no sex but war is okay, so much for "peace and love").
It's not like you can't create with the iPad. But the thing is not a general purpose computer to begin with. It wasn't meant that way. Apple optimized ease of consumption, and for that they sacrificed everything that got in the way, including creation.
I'll slightly amend my phrasing: for production, compared to a general purpose computer, the iPad is worth next to naught. And Apple likely doesn't care, though it would be bad PR to admit it.
Now if Apple suddenly gave you the root password, that would be another story. My argument would be limited to the form factor, which isn't such a big issue (just put your iPad on a docking station).
IMS-20: http://www.youtube.com/watch?v=hJSyPW4BFgo
nLog: http://www.youtube.com/watch?v=PkjiSIPF-Ho
Not to mention iWork and a host of other apps.
Yes, the iPad is really good for consumption, but it's quite good at production as well. And it will get better with time.