Not only is it bringing a new and interesting life to Macklemore's music, it's reviving two forgotten films that show off some pretty amazing dancing mixed with modern day video remixing that just adds a lot to the song. I think that the song along would be a lot less without the video.
Remixing are a good thing. We all remix things even if we really aren't aware of it. When you talk about a song or movie in a quote along while watching someone streaming a video game or sports game, you've remixed that experience. You've created something new. The context of the game you're watching triggered a memory that you associate with that movie, tv show, or song. Internet memes are all remixes and these highlight the need for more things to be entered into the public domain. No one wants the owners of "Grumpy Cat" to go around suing anyone that makes a meme using their cat. They've registered a trademark for Grumpy Cat, so it really could happen.