What's the reason I have this "Add C++ to Module" as the top choice when right clicking files in the project view? C++ is nice and all but this doesn't seem like a common enough action to warrant such a prominent position

It's fair feedback. I don't think the C++ team gave it a lot of thought. It should be easy enough to move it down. What would you move up instead?

Obviously not a huge issue but I'd just move it down a few steps so the others more commonly used float up, e.g. cut/copy/paste, find usages, refactor, delete, git...