HTTPS is not rigid and costly for a single connection. It's rigid and costly because it prevents simple options for caching like sharing google hosted jquery. You can still use a CDN, but then you have more complexity in managing your certificates and pay 1/3 more (Cloudfront pricing).

HTTPS is manageable where needed for security. Sleazy ISPs are making it necessary even where security is not a concern -- for example, viewing Apple's homepage.