The point is that descriptive names tend to either be overly generic (also a cognitive overhead, especially when you have multiple such generic names), or too specific and therefore quickly inaccurate (and even larger cognitive overhead).

Oh, and as for "If it's not that big rename it" - this article is specifically about things that are hard to rename (e.g. public facing APIs or libraries):

> Now, if a name is going to be easily changeable forever, please do make it descriptive.