Yeah, I don't get what the author or any realistic logical person expects. It's an unregulated range open to the general public and with no on-site "waste management" resources (ex. dumpster) and no "authority" representation of any kind, short of the occasional ranger.
The people who create the bulk of the mess...
- are not Calguns members
- are not NRA members
- are not CRPA members
- are not members of any other gun rights organization
- likely don't follow or give a damn about gun laws
- most of them don't even abide by existing laws
- are regulated range rejects (ex. banned/asked to leave for not following the rules and/or state laws)
... the list continues.
The only mess I left when I was up there last consisted of shell casings because there are literally thousands of them on the ground in every direction, and paper targets because other people were already shooting at them down range.