Perhaps it makes the surveillance tooling more uniform and easier to develop/maintain.
The argument that HTTPS is always available and not filtered is just wrong, anyone who has experience working with large corporations knows that clients use local * certificates and everything is decrypted by the firewall and then re-encrypted. Making HTTPS slow af and sometimes plain broken.
I guess someone will implement a full HTTPS stack in js and announce HTTPS over HTTP to go around this "problem".