Nepotism comes to mind. Bad teachers are not protected by good teachers. Bad teachers are protected by bad administrators who recommend them for tenure in the first place. Grow a spine and fire them - who cares if that bad teacher is "cousin Tom's step-son" who once taught your kid how to play catch. Who cares if that "bad teacher" is a pretty good coach. Stop giving them good evaluations and protecting their job! Tenure is not the problem because a bad teacher can be fired for ANY reason in their first 5 years. A really good teacher does not suddenly become a bad teacher - they were that way from the very beginning.
Tenure does not protect teachers who do not do their jobs. It only establishes a fair procedure to go through to remove inadequate teachers. Four years of probationary teaching is enough time for district administrators to decide if a teacher is worth retaining.
The legislature is only wasting time. A good administrator and administrative staff would and should be able to identify an unsatisfactory teacher within the 1st year of the teacher's probation. The administrative team should be able to work to help the teacher to become an outstanding teacher. If there is not a change by the 3rd or 4th year, Why give tenure? If tenure is given to a unsatisfactory teacher, the administrative team should also be fired for not doing their job. There is a format to get rid of unsatisfactory teachers after they have received tenure. Administrators have to do their work.