Twitter is a private organization, and like all private companies, they get to decide for themselves what is acceptable on their platform. Individuals also decide what they find acceptable and choose to be on a platform or not.

Twitter is free to have such ads if they like and the journalist is free to report on what kind of content they find on Twitter. It helps more people know and decide if they want to stay on Twitter. I've left because of the content problem, generally, not just ads. Elon gutted the moderation team and went with a sorta free speech absolutism. The fallout from that decision is increase spam, hate speech, and toxicity. The good people and advertisers are in an exodus.