If the window is poisonous then destroying it to replace it with a good window may result in a net gain. The fallacy begins when people start smashing perfectly good windows.
I'm familiar with broken window fallacy. Not sure how it relates to my comment. That's like saying we should give up on improvements in any developing region because they're in a bad neighborhood. Quite defeatist I'd say.
This is different. Rather than let money sit, you create something stupid which isn't perfect but better than nothing. It has good arguments against it, but it's a more reasonable idea.
Also even if Broken Windows Theory is wrong, that doesn't mean give up on a region. It means fix underlying issues.
I however think Broken Windows Theory is correct. It brings back pride, but I take it at more of the literal sense, fixing the look of the neighbourhood, not criminal enforcement.