Here we go again; let's make it everybody else's responsibility to protect children from incompetent parents.
It's annoying enough having to enter my password to get apps - especially free ones.
No excuse. If it's too complicated, then stick to a Nokia 3210, or at least do some research. There's plenty of help on the 'net.
If you are in the business of selling iPads (which Apple is) you don't want to limit your appeal to only those that will look up and research in detail how everything works.
So for those who didn't google everything about there new iPad, it is a small price to pay to add password protection on in-app/app purchases to help those that dont understand them.
Obviously, if didn't bother you too much. You still have an iPad.