Why do rich people throw away good stuff?

I'm a dumpster diver, I love doing it in the Nashville West End/Belle Mead area. One thing I've realized is that the richer people tend to throw away good stuff like computers, designer clothes, jewelry that can be pawned, etc.. While in the poorer areas people actually throw away trash. I know it sounds gross but you won't believe the stuff I find inside dumpsters! So why do rich people do that instead of donating it or giving it to charities?