My hot take on this:
- If hundreds of thousands of developers are ready, willing, and able to take the plunge on alpha/beta/some-other-form-of-pre-release version of the software, well then good on them.
- #1 works to inform the question of “is it responsible” if one considers that a development platform or framework is software like any other. And the way to get to “working software” is to put it out there to the users (in this case, developers) and see what works and what doesn’t and modify along the way.
- And while I stand by #2, I don’t believe that a Great Job™ has been done of indicating that Angular 2 was pre-release. No matter how many “RC” tags you dangle off the end of the version number, it’s a massively anticipated release and that is likely to color the response w/r/t/ adoption and/or willingness-to-adopt.