When you add up all of the ridiculous hoops web developers have to jump through for cross-browser compatibility, a non-JS UX is the least of their concerns.
You're asking web developers to come up with two methods to accomplish the same goal, which doubles the number of ways the app can break. It's totally unrealistic for any moderately complex web application.
Of course they can. The <form> action submits via POST to an endpoint that disambiguates the selected action, and forwards inside the server side to the appropriate endpoint. Shouldn't be hard with a competent framework.
Then, when JS is enabled, you override the click action on the action buttons, so that the <form> action never gets used.