I feel like you've already made up your mind about this issue, and I'm just wasting time typing. Still, I guess it doesn't hurt to try.
What, prey tell, is the "existing system" - the ability to turn oxygen into CO2 year after year appears to be the only system in place once a teacher makes tenure.
It's really not that easy. Criteria for "continuing contract" vary from state to state and district to district, but it is usually some combination of
1) Years experience in total and in the district
2) Level of education, frequently a masters
3) Approval by administration
I received a continuing contract by completing my masters and undergoing several evaluations. At any point, the administration could have decided to NOT offer me continuing contract. As an alternative, they could have chosen to fire me. The only thing the law prohibits them from doing to stringing me along year after year, which I think is fair.
I think its fair, because continuing contract (mislabeled "tenure"), is not a "guarantee of lifetime employment." I can easily think of several things I could do to get fired and/or laid off, and I personally know of several teachers (new and old) who were let go for various reasons. Continuing contract merely means that I can't be fired without some due process. I can't be fired just because a new principal doesn't like me, or a student claims I screamed "fuck" in class, or a handful of parents have it in for me. If you think about that, that's also tremendously fair. Some kind of "paperwork trail" is required in dismissal at many jobs, and if you don't have that at your job, maybe you ought to look in to forming a union!
Since I've gotten continuing contract, I work just as hard now as I did before I got my "magical firing shield". Ditto for all of my colleagues. In fact, I'm hard pressed to think of a colleague who isn't putting in whatever it takes to help their students succeed. The only people that I can think of who didn't put in their best are people who got fired.
Then explain charter schools where student success is either the same or better with a student population choosen by random chance and the schools have fewer resources than public schools?
The data is charter schools is far more mixed than you suggest. Yes, there are success stories, as there should be. Charter schools were initially intended as "test tubes" where innovators were free to try new ideas, and filter the good ones back into public schools. There are also charter schools that are very successful, but also spend a tremendous amount of money per pupil and offer a battery of services in addition to education (see Harlem Children's Zone). I would personally LOVE to see that kind holistic of model spread, but I don't think we have the political will to spend a minimum of 15k per student to offer all those services.
Unfortunately, there is a sizable number of charter schools that operate simply as money-making ventures, and the results show