HN guidelines say one shouldn't question whether another commenter has read TFA, so I won't do that. But TFA explains exactly why it was vibe coded, and exactly why they're mentioning that it was vibe coded, which is that that was the central point of TFA.
I think you have a good point about why people say it was vibe coded.
It might also be because they want to join the trend -- without mentioning vibe coding, I don't think this tool would ever reach #1 on Hacker News.