http://news.cnet.com/8301-30685_3-20121922-264/apples-imessage-is-stuck-in-the-depressing-past/
Let's put it this way, for iMessage to be in
Instant Message service your messages would have to be that, Instant. They are not, they are delivered just like the traditional SMS service in some-what real time. The only "real time" part of iMessage is the ability to see the other person typing. But once the message is sent there IS A DELAY so it can be DELIVERED. Unlike a real IM service which is pretty much near instant.
You are wrong, get over it. Discussion over.