I hear you, Brody. It can be distressing to pour so much love into your work and hope to receive love in return though the tangible artifacts suggest something quite beastly. I actually caught somebody tagging my art with a big sharpie once and got to drag him through a dialog about it in front of his friends.
I think most of the trash is left at night. Conversations, art cars, and even flaming distractions combined with varying degrees of intoxication can cause even the best intentions to fall shallow and alas, the cup is left behind.
I think there is something on the back of everybody's ticket that commits them to an hour or two of mooping. If you befriend anybody who is camped near your piece that admires your work, why not empower them into doing their mooping at your installation? That way, they get to clean something they love and you both win.
When I installed the piece called Zsu Zsu, I would moop in a French Maid dress, just to keep it fun so I would not curse the invisibles that littered there. Try to imagine the profound conversations, ah-ha moments and sweet embraces that took place just as the dying glow stick fell to the ground and know that you and your art inspired that. Mooping is noble work indeed, as many a sage is born again a begger.
Lastly, our environment is dirty, and far from the white walls of the sterile museums. If I build a flat surface at table height I know I'm asking for it and I prepare myself for the worst. Campaigning against moop is like asking bees to stop pollinating. I do the best I can, and watch my own gear so my camp is not blowing away while I pick up somebody else's gum wrapper.