Wait, people actually judge you for not using iMessage? These people…these people aren’t your friends. Or indeed entirely mentally balanced.
As you said, it’s 2017: proprietary locked-in messaging platforms are just an anachronism now. Back in the Blackberry days, BBM really was a platform killer app — because nothing else came close to its feature list.
These days, you’re almost spoilt for choice, and arguably services like Facebook Messenger are a much more natural place to start — because anyone you want to talk to is probably your Facebook friend already, and there’s a good chance you’re probably wanting to share a link you saw on social media anyway.