That is an incredibly tortured sentence. I'm not really interested in parsing tone in an article, that's very subjective. I would be interested if you could demonstrate that Ars was choosing not to write articles about factual things that would portray Musk in a positive light, but you instead basically said "If you ignore all of their positive factual coverage, they don't publish anything positive about Musk at all!"

I have said that they have a strong negative bias. Whether the underlying news is positive or negative is completely irrelevant. Relevant is that they make things much more negative (= less positive) than they are.