Because then the local hipsters would start eating it.
But that's the whole idea behind my proposal. It's organic! It would be a lot cheaper than hiring that cleaning crew to steam and scrape. How many thousands of dollars did that cost? My solution is not only cheaper, but creates a living art and a feeding trough for residents. I've been to Pike's Place Market in Seattle, and stayed at a hotel a couple blocks away. It's a horrible place with zombies roaming the streets at night (what you call hipsters).