I don't use Waterfox but if I did, this blog post would not make me feel particularly good about continuing to use it. It's not so much what they did say but more what they didn't say.
Does this mean Waterfox is slop?
Apart from my detestation of the overuse of this word, no, it is not. Every line of code is my responsibility, the art and design is either done by myself, oftentimes poorly, or I pay someone.
I think someone who wasn't using LLM code-assistants would phrase this unambiguously. "Every line of code is my responsibility," dances around the subject.