Hey guys, I know ALL of you chat with WhatsApp, but can we move to email just for me and my concerns around security that you don't care about at all?
Seriously... you can make completely unreasonable suggestions until you're blue in the face but it's not going to change reality. There are very real social pressures at play in this discussion. Yes, it turns out peer pressure is a real thing and has a very prominent role in this discussion.
Do you really think Facebook would've spent $19* BILLION on WhatsApp if they thought people would be willing to drop it at the first sign of inconvenience? They know they've got lock-in through sheer market adoption of the platform. If they didn't, they would've just stuck with the facebook messenger path they were already heading down.
Let me guess - in your world they're all assholes for not constantly inconveniencing themselves to cater specifically to what you want. Or you just literally have no social life, because picking up a phone isn't really a viable option to plan a party with a large group of friends. And while email will work, when nobody else wants to use it and you try to force the issue, you're an asshole.
It is probably this. It is not a hard concept to understand. I do not force my friends to use other services, and doing so would just be causing them an inconvenience and annoy them. Yes they are friends, but having to be a special butterfly doesn't mean they have to like that.