Re: So easy for WhatsApp to lose all its value in a single stroke
Google has taken a step away from an existing standard (XMPP) because it could not support every single feature they wanted to put in Hangouts, which they would like everybody to use. Works on iPhones, on Desktops, etc. Unfortunately, for the moment, everybody is more interested in creating their own little app and inviting everybody to join than to try to interoperate. The one who becomes the default for talking to your friends will win.
We have a five-horse race: Apple with iMessage, who can boast with all its fanboys, but has the disadvantage of being strictly reserved to iThing users, so if you have other friends, you'll need another app anyway. Then Google with Hangouts, which comes with most Androids, and has also the advantage that all people with a Gmail account are signed in already, even if they don't know. Now Facebook with Whatsapp, who can integrate it and push it to all the Facebook users. There's also Wechat, which is everywhere in China, and that's a lot of people. And Viber ("They're big in Japan"). Oh, yeah, BBM; and Microsoft probably has something but few people care.