Saying an API follows REST but doesn't implement HATEOAS (part of its definition), is like saying a database follows ACID but doesn't implement Atomicity. Or like saying a software is Open Source but doesn't allow use for commercial purposes.
Yet somehow for one of those 3 cases it became accepted to misuse the term that way ("[original meaning] but without this one constraint"), but if someone misuses the term for the other two cases then everyone suddenly cares and insist that people should use a different term to describe their thing.