"Sadly, in Taiwan as much as the USA, experience is undervalued. It is most clearly so due to having annual contracts rather than the possibility of continuity, and in having no senior or leader teachers. English language teachers here operate at the whim of school and government administrators whose principal motives are not always educational ones.
I fear that the situation in the US is that it is easier to quantify exam results using "scientific" methods, than trying to measure more qualitative aspects of the very complex teacher-student-parent-school-community relationship, or even than by attempting to conduct longitudinal (more expensive) studies of teachers' work over several years. It is also easier to keep budgets within limits by hiring lower paid recent graduates than continuing those working higher up the pay scale.
Administrators, accountants and governments like easy, quick answers. What they do not care about is whether or not the measures used reflect the work being performed.
One aspect of all of this that is working against the vast majority of teachers is the small number of those who are stuck in a time warp, teaching the same way year by year, not reflecting on what they are doing, not listening to students, parents and colleagues, not preparing students for the future they will face, refusing to consider the place of interactive and computer-based technologies in a range of teaching tools, and incapable of being moved on due to inflexible tenure arrangements or lack of non-contact positions. While hey are certainly not doing the rest of us any favours by staying, at the same time, "the system" should have ways of ensuring this does not happen as well.
David, I congratulate you on an interesting article, and I will share it as widely as possible with other educators.