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They did away with that since I was young and now they just let the disruptive kids run rampant.
Keep in mind, you only have one chance really to get an education. If your learning is impeded by uncontrollable children, you now have a greater risk of life failure because you weren't able to learn the fundamentals, because a class of 30 was always being disrupted by one or two people. Say you didn't learn pre-Algebra well because of disruption; now you're behind when it comes to the higher level math for the rest of your school tenure and ultimately, life. These disruptions could have major long term consequences for other kids trying to learn.
Finally, teachers' average turnaround is 4 years last time I checked. That means there are very few veteran teachers available to show new teachers the ropes and how to manage a classroom full of teenage kids. Not that it matters, the new teachers will look for other careers within 4 years on average. The cycle continues.