It's all for fun. That's why they accept "donations". If people are willing to "donate" money to see a system trashed and the people running the site are happy to do that service then I don't see a big problem with it. It's not so much a donation as it is in a sense paying to be entertained by such a thing. There are better causes to donate to, so by seeing it as voluntarily and optionally paid entertainment it's less...wasteful? I don't know.
Okay, it's still a waste but then again most entertainment is.
Look at it this way...even if they used that money to buy an Xbox 360 for somebody it likely would've broken down by now. And it didn't eat up their DVDs!