Anecdotal evidence. 2 out of three people who initially installed Mailbox and waited in line with me have gone back to the regular Mail app. I am likely to do so as well soon. Why? While Mailbox is nice, it only adds a single feature: the ability to defer dealing with email till later date. However, its drawback is that it only does GMail. My world also includes Exchange and Yahoo mail. I don't want to have to use separate apps to access my mail.
If they add other types of accounts, great, will talk. But for now, I can see why the OP is calling it 'Draw Something' of email.
If they add other types of accounts, great, will talk. But for now, I can see why the OP is calling it 'Draw Something' of email.