Other thoughts would be glock bulge.
The internet never forgets.
Glocked brass hasn't be a thing for a few generations of Glocks. Glock corrected the issue. That's not to say you don't still come across them from time to time, but this is no longer a serious concern, and if you inspect your pickup brass, as you should, you can find them and cull them from the herd.
The guy who poo-pooed the range brass is a knucklehead.
You have two worries -- picking up the occasional .380, which looks a lot like 9mm, but those are easily sorted out.
The second issue is people shooting 9mm major in Open division of USPSA, which puts a beating on brass. Some people who shoot 9mm major won't reload their own brass after it's been shot at that level even once. Some will load it a few times. Some will load it until the brass splits or the primer pockets stretch. But if you're loading 9mm minor responsibly, and you pick up someone's 9mm major brass, it will reload just fine.
Sometimes brass wears out. Sometimes brass splits. You might split a case when firing it from your pistol. It's not the same as an over-pressured catastrophic failure that tears apart a gun. The steel breech-face and chamber steel are what contain the pressure when a round goes off, not the case. If a case cracks in an auto-loading pistol, you're going to lose some gas, pressure, and powder, but it's not a big deal. You might not even notice. And if you pick up a case that's already cracked, you throw it away.
I pick up brass at action pistol events and reload them. I even bought this "nut wizard" to make it faster:
https://www.amazon.com/gp/product/B007QVUGGO/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1You just roll it over empty cases, and it picks them up.