The simplicity of it is logic defying. It used to be that you had to find crosswalks or move puzzle pieces or type blurred letters and numbers, but NOW all the sudden I can just click a box and HEY!, I’m human?
That’s hardly the Turing Test I’d expected.
Clicking percision and reaction time are still measurable and the checkbox can fall back to other captcha tactics if it has low faith in the user.