[octoberfranklin]

This is cool, but is it really needed that often?

There are some industries (virtually all of Wall Street, for example, and certain parts of government) where the company needs to surveil 100% of what their employees do on the web from inside the office. These companies have been running MITM proxies for decades.

Wouldn't any website that rejects a non-browsery TLS client be blocking out these people as well?

[lwthiker]

They don't block you completely, just present you with a JS challenge that delays your access to the site. A browser, even if behind a MITM proxy, would be able to solve this challenge.