How, pray tell, do you quantify your claim that the homeless are often the perpetrators? I could just as easily say that rich spoiled brats, like the albatross killer, are the true culprits. 
We could even take the wild speculation one step further, and accuse the toilet and sink manufacturers of sending out vandals to ensure they can sell more fixtures. For that matter, maybe the C&C workers themselves are doing it in the name of job security?

Isnt baseless speculation fun?