It's bugged me that this whole song and dance of wifi portals; unencrypted wifi, dns spoofing, and sign in pages have been around for over a decade and none of the wifi revisions formalized this. It's been a kludgey cat-and-mouse where the OS checks captive.apple.com and gives you a modal pop up, some wifi networks let you send iMessages and gmail, but wont let you browse without paying. In then end you're still using unencrypted wifi.
I've heard there is finally some future wifi spec formalizing open portals that negotiate to an encrypted connection.
As it is, connecting to "free WiFi" just isn't worth the hassle of clicking through T&C pages, and paid WiFi is even worse.