Does Mythbusters make up myths?

Some of the myths on Mythbusters I’ve never heard of, or seem more like something stupid a handful of high school kids joked about than something they really thought. I remember one where they said that the myth was that an empty beer bottle will do more damage when smashed over someone’s head than a full one. This seemed weird to me because I didn’t think the characters in old movies doing this that they mentioned did it because they were trying to cause more damage, but because they were much more likely to want to smash a bottle over someone’s head once it was empty than when it was full. Does Mythbusters create myths just so that they can debunk a myth that doesn’t really exist?