(Author here) I used to think that, but I've since found myself working on a similar sized codebase where we use very little OO and none of these problems have manifested themselves. Avoiding large function signatures and passing higher order functions around takes a little discipline, but wrapping those things with a bit of OO doesn't make the root problems go away, it just encourages their proliferation. (To reiterate the article, I'm by and large talking application development as opposed to library development).