Honestly, in my view, there are different reasons it doesn' matter
1. Sure they are "stealing" our shit, but whose gonna stop them, graff is illegal. Graffiti on private property should remain illegal, we have to keep private property rights, sure I think the laws are ridiculously too strict, but that's an entirely different issue
2. The more people see graff, the more they may "understand," and the perhaps writers will be criticized less frequently.
3. This goes along with number 3; Graff is at least portrayed positively
4. At least it isn't some god-awful shit and at least the WB or some other shit channel isn't doing it.