What if they ran out of something you ordered? Do you want to drive over only to find out that they haven't started making your order to to the missing ingredient? Or would you rather have them call you and apologize, while finding out what you wanted instead?
Out of the dozens of times that I've ordered, has never happened. And I'd gladly trade it with not having to deal with giving my number for the one time it's happened.
Now, if only they got Seamless…