Your second point is important, but when you have recruiters/HR as the front line of hiring it completely breaks down because they haven't got a clue whether an applicant's skills are transferable or not. And they cop a lot of flack for this from developers but honestly I'm not sure it's possible for someone who doesn't even code for a living to learn how different technologies are and aren't compatible, skills-wise. Same reason we end up with unhelpful job descriptions. I think most developers would already be onboard with your second point but it's simply not up to them.