A magic club sound amazing! And, those look good, but school events typically center around athletics, such as Homecoming. If schools just moved those competitive events to a community recreation program, it would reduce the caste system in schools.
Yes, natural food chains exist, but that doesn't mean we could create artificial ones in our schools.
I bet you never cheered for a magic club.

Or, at a debate tournament.
Nothing against you but I'm not a fan of cheerleading and I spent two years silently wishing my own daughter wasn't on the squad. She'd been a competitive gymnast prior so making the squad was a cinch and she enjoyed the social aspect but it always bothered me. She also played tennis and at the end of her sophomore year the two began to conflict so she dropped cheerleading - and I was thankful. Many of her friends remained on the squad and they're all good kids, I'm not saying they're not, but I still think cheerleading is demeaning. That's just me. I wanted more for my daughter.
I'm not denying any of that, but just because a natural pecking order occurs does not mean we should encourage one in our schools. One common link in all of these shooters is the fact that they were school "rejects." As you say, a pecking order will occur naturally in life, but in a school that's paid for with taxpayer dollars, every effort should be made to keep it from happening. And, if we're going to put emphasis on anything -- it should be on academics -- not on athletics.
I'm not making the claim that we can keep these kids from becoming shooters -- there's something messed up in their heads -- but by removing the extraneous crap from the schools, we might be able to lessen the artificial caste system and decrease the risk. And, gawd knows, it'd be a super side effect if our kids started learning a bit more, too.