You're right, the HomePod is not a replacement for a soundbar, or full-on surround system. However I disagree with the assessment that Apple never intended the HomePod to be used to watch TV.
Since the HomePod can be used as audio out on the Apple TV, I find it very hard to believe that the people at Apple never thought that people might only use it to listen to music "as intended." Of course they knew people would watch TV while streaming the sound to a HomePod.
So if a person, let's use me as an example, simply wants better sound than provided by the built-in TV speakers, and already has an Apple TV, then a HomePod is a completely adequate device. I don't currently have the room or the strong desire to setup a new surround system in my small flat at the moment. So the HomePod is an ideal solution for me. I get really, really nice music playback, and I get TV sound which sounds great. There have been a couple of times, since I bought the HomePod, when I was watching a back episode of Law and Order: Special Victims Unit, that I almost thought I did have a surround system. When the audio source has good sound, the HomePod is really outstanding. When the audio source is 2-channel stereo, the HomePod is still very, very good.
As a middle ground device between a full-on surround system and the TV speakers, the HomePod fits in very, very nicely. The people who say Apple never intended the HomePod to be used this way are, I believe, mistaken.
Be that as it may, how many users live in a world where the atv is their sole source of tv entertainment? Right now HomePod would work only for those users and I bet you any half decent tv sound bar will sound better in comparison.