To be fair maybe people don't want to give out their email to everyone.

I've never, ever hesitated in giving out my email address to anyone (that includes sites that I know are scammers and would sell my email address to anyone practically for the asking). In the past ??? years (since GMail was in beta), I've received less than 5 spams.

(I know it's a little irrelevant to your point though, but wanted to say at least with gmail you don't need to fear giving you email address out)

Lets remove all newspaper apps too because e-mail would do the job. Also remove all other communication because e-mail would do the job.</sarcasm>