I see what you mean.On the other hand I find their purpose as a way of describing a notion. For example Wikipedia has this to say about Perl6 type system :
"In Perl 6, the dynamic type system of Perl 5 has been augmented by the addition of static types" and
"Perl 6 offers a hybrid typing system whereby the programmer may choose to use Static Typing, Dynamic Typing or mix the two"
Looking at those sentences the terms dynamic, static and hybrid are mentioned to promptly describe a notion.I don't know if that could be done otherwise.Or for example what hides behind the term MMD.I think the arguing starts because this notion could be considered open to interpretation and not because of the terms themselves.For those reasons I think that terminology is needed