It's not, people just like to argue. A "universal" message is a text message, and BB Messenger was from the days where text messages were expensive, and before threaded messaging became commonplace on iPhone, Blackberry, etc...
Today BBM is entirely relevant for BB users, but so irrelevant for the rest of us. Having had a blackberry it's a great tool for bb to bb user communication, but the world is no longer dominated by BB users.
I love how people argue for the sake of arguing for points that are obviously invalid. No, Whatsapp is NOT commonplace. It's an app that's been around, few use, and it takes two people working together to establish connection through (ie. you have to make sure the other person knows to buy the app, install it, and manage that it's always running).
Just look at the tons of peer-peer messaging apps out there... none of them are going to gain mainstream adoption. If google\skype can't do it, nobody will. And no, they're not "mainstream" ... how many messages have you sent through either of them vs the built in messaging app in the last month? See. 99.999% of us send messages to domestic destinations (be it US to US, UK to UK, etc), so the built in works for the purpose. For those niche users who need it and want the tradoff of cheap\free international messaging and are wiling to take the hassle of Whatsapp, fine.
PS - Calling anyone who opposes your opinion a "cry baby" won't get you far in life. Just makes you look like a hypocrite to say you can express opposition opinion but others can't.
