In fact, my use of all these technology is probably equivalent to email or SMS for a group of friends that is email-based. What is your opinion of people who refuse to get an email?
Not the same thing. Having an email address does not require any privacy tradeoffs.
I don't know anyone who "refuses" to get email, but I know a lot of people (believe it or not) who don't have computers. But they have phone numbers. I have to remember to leave them a voicemail when I email everyone else. In those cases, consideration > inconvenience.
You don't get it because your social circle doesn't live and breathe Facebook. For me, refusing to get a Facebook account would be the same as refusing to have an email account to you. Try talking to some middle schoolers or high schoolers - they are even worse than myself.
Again, I want to stress I do not approve of Facebook's stance on privacy and I do not disapprove of your stance on the platform or its usefulness - it is useful to some people, not all.