I tell you what, if you're a young person you can be publicly shamed for having the wrong color bubble, or outcast by being excluded from a group chat. To you and I that probably doesn't make sense, but for a big portion of the young, phone using population being unable to participate in the iMessage ecosystem is a huge deal socially. You are essentially excluded from the friend group, you're excluded from conversations, and it carries over into real life because you've been excluded and that carries an impact -- you're an outcast. It doesn't have to be rational to be true.

Being excluded from a group chat has a huge social impact for younger people.