Because it's just there on devices they have. It is the default for tweens and teens who just got an iPhone handed down from a parent, and it works on day one.

Because it's just there on devices they have. It is the default for tweens and teens who just got an iPhone handed down from a parent, and it works on day one. Regionality happened with IM clients back in the day as well - some areas favored AIM, some Yahoo, some MSN. Why did that happen? It just does.