I'm not sure why you've been downvoted, I think you're quite right. A warning that's shown too often when there's no real threat gets ignored. Making the warnings bigger and scarier is just crying wolf ever louder, and it doesn't work.

I don't think the solution is to avoid HTTPS, however. I think sysadmins need monitoring and automation tools so that expired certificates can be an exceedingly rare event. Letsencrypt has taken a big step towards this by making a fully automated process to get a certificate.