FSF has the term 'free software', which is well defined as to what qualifies as free software. In fact, it predates the term 'open source'. OSI created the 'open source' definition based on FSF's model.
But like the term open source, there are those around with malicious vested interests who insist that these terms are generic and the publicly accepted strict definitions don't apply. Their intention is to take advantage of 'free software' and 'open source' tags without making the necessary compromises.
Any new definitions will have the same problem. The only solution is to call out the above mentioned people for dishonesty and their attempts to take advantage of FOSS definitions.
I don't think anyone can sue them, unless the terms 'open source' and 'free software' are trademarked. I doubt that they are. Any party can be sued for violation of licensing terms. But these definitions aren't licenses by themselves either.