Although I agree with you technically, isn't that going too far too fast? We know that majorities' resistance to change is high, so we need a hybrid solution in the short term. Is the associated risk/reward ratio worth spending so much energy to get people on SimpleX? I'm not convinced. The world would already be so much better if everyone used signal...
Discussion
i've moved from friend and family from SMS to Google Talk, to Google Hangouts, to Google Allo, and lastly to Signal. it's just the next iteration to find something better and it's pretty painless.
I've done the same, but I realize that these people only use Signal to communicate with me, because the rest of their entourage stays on Whatsapp. That's why it doesn't really bother them to change once again, it's just one roving conversation to be moved again. I think we'd have more to gain by choosing one good solution and concentrating on that rather than changing as soon as a slightly better alternative is available. There will always be geeks scouting ahead but that is so that the majority can progress safely and smoothly.