That's the point of the article, no? For a business, they can choose if they want to define a bug as "does not work to spec", or "does not work to user expectat

That's the point of the article, no? For a business, they can choose if they want to define a bug as "does not work to spec", or "does not work to user expectation" (I believe we agree there, that this is a distinction without a meaningful difference to development) So, for the developer, the activity is the same. Given most software is existing and not green-field, if you extrapolate this idea out further, it implies that feature and maintenance work have a lot more overlap and are fundamentally the same thing for even larger projects /features than just small bug fixes. It raises the question, at what points and when does feature work and maintenance work become distinct activities?