I assume the logic is that they don't trust kids to not mess around with them or idk give them to other kids or something? My high school said they didn't let kids carry around meds because they didn't want us "sharing" them which...what?? You can't get high off of an asthma inhaler or an epipen?? Insulin costs a fortune why tf would anyone share it with someone who doesn't need it???? And like, idk I can understand being a little nervous about a literal child running around with a syringe in their backpack, and we do put child-safety locks on certain things for a reason, but what they don't understand is that most kids who have life threatening medical conditions are very aware of the fact that their inhaler or insulin or epipen is NOT a toy and not something to mess around with or waste or let other kids play with. That shit gets BURNED into your brain. I had my first life-threatening asthma attack when I was a toddler, I was VERY well aware of what would happen if I didn't have my inhaler with me when I needed it, and I was extra careful with it, I never let anyone else touch it, I didn't even fiddle around with it which like, my ADHD ass fiddled around with everything, my inhaler was the exception.
Kids aren't as stupid as adults think they are, and disabled kids(asthma, diabetes, and life-threatening allergies are all disabilities, fight me) are capable of understanding the severity of their medical conditions and taking care to keep their live-saving devices with them without causing an incident. Also, while other kids can be assholes and bullies, the solution to that is to teach kids to respect their disabled peers and maybe have the teacher keep an extra inhaler or epipen with them in addition to the one the child has, just in case, and like even then overall in situations where a kid has an asthma attack or goes into anaphylaxis, a lot of the time the other kids are the ones who are helping the disabled kid and fighting with any teachers/adults who aren't taking the issue seriously. Children very much understand that these things mean the difference between life and death for their friends and classmates and a lot of the time they will try to help, which is honestly something to be encouraged! I want abled kids to know if the teacher isn't taking an asthma attack seriously they should raise fucking hell about it. Kids aren't stupid, they understand the severity of this kind of stuff. And if they don't we should teach them rather than force disabled kids to risk their lives just so abled kids don't have to learn to not be shitheads.
Also, a lot of abled people just don't understand how serious these medical conditions actually are, or assume people are over-exaggerating or faking to get out of class. My PE teacher in middle school legit thought I was faking my asthma to get out of class even though I had a doctor's note, even though he'd SEEN me have an asthma attack with his own eyes. He constantly put my life at risk forcing me to work out until I was wheezing and then acted pissy when I said I needed to go to the nurses office to take my inhaler almost every day. He was also supposed to send another kid or teacher with me to make sure I didn't fucking die on the way and half the time he didn't. I learned how to force myself to breathe through a mild attack just because it was the only way to keep myself alive in a system that legit didn't give a shit if I lived or died(which backfires because if you learn to cope people think you were just being lazy before, it's a stupid fucking cycle). People will say like, "oh you wouldn't tell a person with asthma to go without their inhaler or someone with allergies to leave their epipen behind" but people do that all the time, and it kills us. A sufficiently ableist teacher might not accept that a kid's life is in danger until the ambulance shows up, and even then sometimes they'll still insist the kid is faking or making a big deal out of nothing or pull the "well in my day kids didn't have [blank]" (newsflash Brenda, back in your day kids just fucking died of this!! that's why you don't remember them!!) or whatever. Sometimes the kid actually dying isn't even enough to convince these people children have actual medical problems that must be taken seriously. They just think kids are stupid and disabilities aren't real and it costs the lives innocent children every single year.
This shit extends to adult doctors too, my cardiologist got mad at me for not being able to do a stress test because speed walking for 5 minutes triggered my asthma badly enough I needed to stop and take my inhaler. He legit acted like asthma wasn't an excuse and that someone my age should be able to walk that fast for that long no problem, so I clearly just needed to work out. I had an asthma attack IN HIS OFFICE and he still acted like I was just lazy and out of shape. Even medical professionals don't think these conditions are actually that serious despite VISIBLE PROOF to the contrary. (And that's not even getting into adults who die in jail because police don't care about making sure they have their meds.)
And like, some of it is this like weirdly prevalent idea that kids can't be disabled? I'm nearly 29 and I still have doctors insist that I'm simply too young to have arthritis or chronic pain. People think only the elderly have real health problems and kids are just always magically healthy because acknowledging that young people can be disabled makes them uncomfortable. It's so fucking stupid but I encounter it ALL the time and it does so much harm. Doctors not believing my chronic pain until I was like 25 is part of why my pain is so bad rn. If I'd been believed earlier I could have had preventative treatments and my joints wouldn't be as damaged as they are now. I also had a disability advocacy group legit tell me they couldn't help me get on SSI because it would be too hard to prove someone my age can't work. It's insane. These days anyone saying "but you're so young" to me no matter how genuinely they mean it makes me want to punch them. Age has nothing to do with this. Stop projecting your discomfort with how fragile human health really is onto me ffs.
But yeah, it's legit a mix of thinking kids are too stupid to be trusted with their own medicine, left-over "war on drugs" bullshit ideology, people not believing kids can be disabled, and systemic ableism.