Like the LGPL is confusing because it is not written well in some sense. But that goes to "confusing" instead of "unenforceable".

But yes, better written the problem with this license would just be "They are trying to claim things they know they can't claim" instead of "they are actually claiming things they know they can't claim".

The next question that would pop into my head would then be "At what point does attempting to claim rights to things you know you can't, as a way of scaring people into paying you, cross into unfair and deceptive trade practices"