Interesting post, Karl. A few thoughts in response to the post and the comments...
• There is certainly much that can be improved in most schools when it comes to teacher training, induction, evaluation, professional development, compensation, and the granting permanent status ("tenure"). I don't know anyone who truly "defends the status quo" - except in the sense that some proposed solutions are worse than the status quo.
• I would hope to see a broad consensus among educators that the Vergara ruling is off base. The ruling mainly cited economists' studies and superintendents' (limited) personal experiences. The plaintiffs were almost irrelevant to the case. Some of them were in charter schools not covered by these ed. code statutes; the others never proved that ed. code had denied them a constitutional right, nor did the judge cite any individual plaintiff's testimony or experiences in his ruling (if I recall correctly). The plaintiffs did testify about some bad teaching, but there was no proof that able administrators tried and failed to address the problem only to be undercut by ed. code. Bottom line - bad teaching is not caused by or perpetuate by teachers' due process or seniority rights. Otherwise, we'd expect school systems that lack these rights to show evidence of better teaching. The main problem is under-resourced, over-stressed systems; when teachers and administrators have what they need to do a better job, they typically... do a better job.
• The reasons anyone might have to cheer the end of "tenure" deserve some scrutiny. Weak teaching persists in places without job protections, if there aren't a host of other reforms and resources in place, but all teachers in such settings are more vulnerable to pressures and politics that we are better able to withstand in systems that do have "tenure."
• This one relates to one of the comments: seniority and permanent status are not the same thing. A "tenured" teacher can get a pink-slip too, so linking these issues confuses the issues a bit.