No child left behind was the most disastrous cancer to infect public education. We should absolutely segregate the kids who don't want to learn from those who do, instead of dumbing them all down.
I went through an under-resourced education system with 50+ students per class and bused 3 hours per day to a school with gangs and drug problems because of my race. All the while, I was bored to tears with material already covered up to 2 years previously in private school. (Dad was a cheapskate and wanted more money for buying stereo equipment, and so Challenger had to go.)
I remember a teacher in high school throwing a textbook at a student that wasn't paying attention. He paid attention after that. I suppose times and approaches to teaching have changed.
Sometimes, students recognize the barriers around them and exploit them to their fullest potential. One student pays attention after getting the book thrown at them, another observes how the teacher aimed for the floor and tests their patience because they know they won't get hit no matter how many times they zone-out. It's disappointingly easy to bait educators into disproportionate escalation, in my problem-child experience.
The lesson you learned from this experience was that the adult was being childish?
The lesson I learned is that if you beat certain people at their own game they will never let you live it down. Whether I was dysfunctional or not, their response didn't work and they refused to renege after months of failure. They failed as a teacher, when I hadn't failed as a student.
I dont think you can enhance learning thru fear, there is no way that you get people to be more engaged and retain information presented in that environment.
Perhaps "Kids who don't want to learn" is not a constructive way to look at the issue. Maybe "Kids who are engaged with something other than what is going on in the classroom" would be more useful. That goes for covert books, magazines, hunger, lack of sleep, drug addiction, unstable home life, personal drama, or any other distracting factor. Teachers and schools have existing strategies for these ranging from internal and external referrals, social support and psychologists, learning disability specialists, temporary removal from the class, etc. Some students will fail, but you should never brand kids as write-offs or uninterested, that's akin to giving up on them which becomes a self-fulfilling prophecy.
As for separating higher motivation and engagement students from the general student body, gifted and talented programs continue to exist for this purpose. https://en.wikipedia.org/wiki/Gifted_education
I attended such a program in Sydney Australia at ages 11 and 12 then a similarly academically tested high school. In the former and most of the latter case I found it to be quite positive experience, but lack any point of direct comparison. There were still troubled kids, drugs, etc. Mostly it was still slow and not very challenging. However, there were virtually no distracting elements in an average classroom whereas my understanding is that in many countries, high school teachers may often be unable to maintain a genuinely focused and academically engaged classroom. To me, this sounds like a state-mandated waste of time for all involved.
These days, where switched on kids can grok arbitrary subjects through the internet within seconds, what's the point of rote schooling? Perhaps we need to reduce the classroom hours expected of children and increase other activities, this would partially recognise the declining utility of rote knowledge in the workplace. This touches on the greater social problem, which is that post industrial revolution schooling largely performs a child minding function. What do we do with the kids if they're not locked in school? State and other schooling often also seeks to ingrain what IMHO are various negative, outmoded and incorrect ideas (much of religion, false assertions of the representative nature of a local "democratic" system, nationalism, etc.) in the student body. Home schooling is a good antidote but comes with its own challenges.