It's difficult to read much into this because its not a well-defined phenomenon, and linguistic patterns like this are more often about convention and happenstance than an identifiable reason. I'm gonna point you to two other answers, but these shouldn't be taken as definitive.

As I and /u/qhapaqocha discuss in this thread, the label "civilization" is not an academic one, but one more tied to the political and publicity interests of certain authors. While it's not a banned term in academic writing, it's not an analytical term: whether or not something gets called a civ isn't essential to any point an archaeologist makes. Often, it's used simply as the broadest possible term for a large collection of related cultures. I would never say "Inca civilization," but might use "Andean civilization" when referring to broad trends across thousands of years in the entire region of interconnected peoples. This is one reason why we might see "Maya civilization" more frequently than, say the "Mali civilization;" it's common to see "Mali empire" because that's a more specific term, but there was no single "Maya state." Like ancient Greece or Renaissance Italy, they were a collection of independent city states, and so it's hard to apply another term.

It's also very easy to jump to the "because racism!" answer, but this ignores some nuance. As I've described in this answer, there was, in some cases, a decided effort to count the Maya or other groups as equals to the Classical European civilizations. Was this Ameri-centricism? Hardly. In that case, the French were interested in hyping up the quality of their imperial territories for their own gain.

Even given these, however, it's more productive to understand the broader context in which these terms are used. That's where any issues lie.