Really, there is no reason why a form should require JavaScript. When jQuery was hip, the js community celebrated "Graceful degradation". I frequently have the feeling this attitude is lost. That's super sad because it also excludes all the handycapped people.
Does even anybody remember the good old HTTP basic acess authentification? This is one of the most accessible ways of protecting ressources, it can be consumed by any HTTP client (!), and it is just reduced to the basic.
One of the worst things are these terrible captchas everywhere. I wonder why we cannot come up with a web standard interface in a way the captchas could be offloaded to customizable and adaptable GUIS rendered by the browsing client. This way, clients (users) could even declare what kind of captcha they can solve (blind people obviously cannot read images).