Only if it's used as part of a (simplistic) algorithm.
And besides, why would students want to fire the good teachers? That doesn't really make sense. (As someone who was sent to the principal's office on a semi-regular basis.)
Later, whenever I met a new teacher (at university, in the workplace) lessons always seemed easy to me. I had to work hard for a good grade at high school, and her tests demanded precision and attention to detail. I started to appreciate her more.
Students are likely to prefer teachers with a pleasant attitude and lower difficulty level. A teacher easy to distract with an off-topic conversation. But at the end of the day, a teacher's job is to teach. Sure, a great teacher would combine that with charisma, ability to inspire and natural charm, but nobody's perfect.
Win!
Part of the reason you see so much backlash from teacher's unions against these initiatives (despite the fact that virtually all teachers acknowledge that some are better than others, and have a pretty fair idea who the worst ones are) is that they don't see this as a way to fairly evaluate teachers and improve the quality of education. Rather, they see it as a weapon to be wielded by school districts, school administrators, and angry parents ("Mrs. X told little Johnny (age: 17) where babies come from!" "Mr. Y is a member of $MARGINALIZED_SUBGROUP!" "Ms. Z believes something that is the current scientific consensus" "Mr. Q gave my son an A-") against unpopular teachers. It is an unfortunate fact of life, and even more unfortunate that so few are willing to admit it (especially here on HN, where the quality of discussion is usually above average).
We would probably have much greater buy-in from teaching unions if these evaluations were perceived as something other than politics as usual. Unfortunately, the proposals all seem to keep a some level of human involvement in the firing process (so only the very most outstanding teachers are immune to the usual political pressures). It's useful at this point to recall a bit of history: Teachers today are so hard to fire because they have tenure. Teaching unions successfully forced tenure the tenure system on school districts because school administrators of the past abused their authority to fire good teachers who happened to be politically unpopular.