The idea of tenure is as destructive at the college level as it is for public-school teachers at the elementary and high school levels; I remember enrolling in courses where you would rarely see the professor who was listed as the instructor of the class.
The whole basis on which the education industry was built up (by which you would improve your alary prospects by investing in education) has crumbled; if anything, the reverse is true: the more you can command in salary, the harder whole industries are working to either 1) have the work done elsewhere, or 2) import foreigners to do it here for (much) less as indentured servants (even if it means training them here to do it). Because of these trends, Americans are looking a lot more closely at how “education dollars” are being spent, and they’re not happy; they are paying more & more for an education worth less and less.
Tenure more or less gives the educator a vested right in the job, he/she can be forced out with a little ingenuity. As in any other line of work. I once worked for the highway department and in this office there was a totally incompetent engineer whom they sent out to do stuff that only required an inspector to handle. He got all the s-—details, and did those so poorly that only the kindness of the boss kept him from being transferred. Anyone with pride would have been long gone.