Nobody is arguing that the intention was simply to post the song. They're saying that a portion of the song was used illegally and without permission.

Also, 29 seconds is ~30 seconds, which is the length of a standard TV commercial. In a world where all identifiable samples need to be licensed, that's not "very short" at all.

I know that telling people they're categorically wrong when it comes to copyright is perceived as defending copyright. I want to be clear that I recognize the need for substantial copyright reform and liberalization. When I say "you're wrong" I don't mean that reform and liberalization are bad things. I simply mean that you have no idea what you're talking about when it comes to the law itself, and how it actually works. I think widespread ignorance is a bad thing among those who (quite justifiably) would like to see the law changed.