I'm genuinely surprised that copyright is being used to control the use of a "scale" in science, and that the legal threat was used to take down a paper criticizing it as "no more accurate than flipping a coin".
Wouldn't science be under the umbrella of fair use, and publishing papers be under the umbrella of educational use?
It's undoubtedly a money-grab, and it reminds me of the people who extorted restaurants, etc., for singing "Happy Birthday", until the courts ruled that the song was in the Public Domain already (and had been for a very, very long time).