[algorithm_dk]

Because the apps can initiate a call by just pointing a webview at tel:0000. Another reason is hybrid apps, imagine a contact hybrid app running in something like PhoneGap. You want to click a button and call right away without the phone asking you to confirm your action.

I'm not saying that Apple's design is good, but it is documented.

[aye]

That was my thought as well. I'm sure the decision was made to connect as seamlessly as possible, without the user having to stop and click a dial confirmation.