I guess I don't really see why some people are so attached to iMessage. I guess I'm not a power user. WhatsApp or a regular text works very well for me. A messaging app wouldn't dictate my platform choice. I know there are plenty that do. I just personally don't "get it."
Ditto.
I mean, I get it, but to me it's certainly not enough to keep me on iOS. Everyone has different needs, so kudos to them. But as you mentioned, there are so many other popular messaging apps, plus there are regular SMS/MMS texts that most carriers (US) offer unlimited supply of, I just don't find the need to be on a certain platform just for the convenience of messaging. Sure, continuity is great, and it's something Hangouts/Allo should eventually adopt (honestly, still shocked it isn't part of Allo. Just baffling on Google's part). Until then, it's not a feature so paramount to my day to day communications that I must stay on iOS to have that feature.
The majority of my family, friends, and coworkers have iPhones. I have zero problems chatting with them.
I can't help but think of BBM when people used to say they stay with RIM just for BBM. You get very similar responses often: "I can't leave iOS because of iMessage." With the proliferation of chat/messaging apps today, such a saying just doesn't ring necessary to me.