Some people just don't care about their windows.
However, I never like cleaning those properties where the insides are so filthy, it's pointless doing the outsides.
I remember doing one, thinking, 'It looks no better now than what it looked like before I started', it was just a minging house full stop. I disliked doing the place because it made me feel like a con-man; what was the point? I couldn't really avoid it too, because I did the rest of the street.
I was quite relieved when the lady told me that my services were no longer required.