Does that make my Civic coupe a sedan?

Does it have a B pillar behind the door and functional back seats? Then yeah. It's a two door sedan according to Wikipedia.

Maybe the confusion is popular or common terms versus technical terms.

kleinbl00 and I kind of talked about that back and forth a bit. What an engineering team might classify the car as and what the marketing team might classify the car as depends on their reasoning. Take it even further, regulatory agencies, whether for racing, emissions, or safety, all have their own criteria. It's a fun thing to talk about, but obviously not everyone is gonna agree.

That might explain my annoyance with the author. Nobody likes the guy at a party who declares a tomato a fruit. I don't think he knows his audience, or he's deliberately being obtuse to try to feel smarter than them.

I think when car journalists write their opinion pieces, they have in the back of their mind a goal to get as many angry letters to the editor as possible. If you ever have a weekday afternoon where you find yourself bored with nothing to do, go to the library and look at a few back issues of magazines like Car and Driver and Motortrend and read the letters to the editor. People get their panties in a bunch over the smallest of details.