The only reason those captive portals don't work is because the operators decided to use the huge hack of a solution that is MitM'ing unencrypted HTTP traffic a

The only reason those captive portals don't work is because the operators decided to use the huge hack of a solution that is MitM'ing unencrypted HTTP traffic and/or messing with DNS instead of working to ensure a standardised solution (such as RFC 7710) was available before rolling out this sort of technology. The current approach really is a joke. To be honest, I'm glad it's now back-firing with more sites using HTTPS (that they can't hijack connections to), maybe this will nudge the operators into doing things properly - whether that's using WPA Enterprise for username/password auth or using the DHCP option to tell new clients they need to visit an internal URL first to use the internet (no connection hijacking required).