Because there are many on here who consider paying $100 for being able to distribute on the App Store outrageous. They don't realise that just putting in 1 hour of your development time to create something usually costs more than that.
The point is, you don't need to pay to develop an app, you only need to pay for submitting it into the app store. So perhaps I should have added a disclaimer to my statement and not just limit it to precisely what I expressed.
I did not intend to make a statement about the submission fee.
