The agenda is to highlight when Trump and Elon blunder but ignore neutral or positive stories. Go to the front page right now and look at the articles, I see four mentioning Trump that are negatively charged. That isn't to say any one article is untrue, but hard to miss the curated pattern
Gitlin, at least, also
slants the negative news. The story on sales about Tesla losing market share to VW, but other outlets reported it as VW gaining the top spot.
They've always had more coverage of Tesla than other automakers, or at least I've always noticed it more. When Tesla was leading EV sales they dutifully reported that, when they're dropping they report it just as well. If anything slanted coverage would be reporting less on Tesla because they are doing badly, which seems to be what you want.
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.