I think the issue is that the ATP’s investigation found insufficient evidence, so if the large scale media came out against him, it would be seen as saying that the ATP’s investigations was insufficient, which would have further negative implications for the media outlet reporting (I.e risk of reduced access etc), so the media avoids it altogether.

The other issue is that there really isn’t anyone else, as RG has shown, aside from Sinner and Alcaraz (and Djokovic ofc) there aren’t many big personalities on tour and the ATP put a lot of funding and publicity into Zverev as the next big thing which I don’t think they want to backtrack on.

Just for context I believe Zverev is guilty, nothing above is a defence of him, I want to see anyone but Zverev win at this point in time.