Same folks who didn't realize that all messages show up in the same color, the blue bubbles only happen when you send. They're getting SMS spam.
> I just don't want to be locked into a system where that's the only choice.
Who's locked in? I can and have switched back and forth between iPhone and Android devices. My contacts are sync'd between them, calendar, mail, all of it just works either way. Only reason I'm back on iPhone right now is because the churn (and by extension, TCO) is significantly lower. If the calculus changes on that, I'll jump ship again, no big deal.