I use email too. And MMS. And SMS. And IM. But when somebody (like my brother who seems to only know how to communicate with people on Whatsapp from his iPhone) tries to message me via Whatsapp, I'm glad my E7 can have that app and I can stay in touch.

It's all down to individual user preference. You have yours, I have mine. If everything had to be the same for everyone, we'd all be using goddamn iPhones!