On a recent trip to a friend who lives near the KY/TN border, I stopped at a fast food restaurant for lunch. In the restroom these locks struck my 'oh no you didn't' button. Look closely.
Here's my take on this. The lower lock was installed. Someone complained that it wouldn't lock. Doofus can't figure out the problem because he installed it just like all the others...must be defective. He had a solution...by golly he's never had a problem with this kind of lock!