And to me, as a Chinese-American person, it was insulting (and a bit bizarre) to insist that it's "racist" to say the virus leaked from a lab, rather than having spread via an unsanitary wet market. But this was the party line, and many people toe'd it for years.
On the other hand, it seems that there almost zero medical professionals on the left who are interested in debating him and showing how he has been wrong about various topics. He calls for universities to host debates on these topics of public concern, but pretty much no one is willing to do it. This makes me think it is somewhat less likely that he is just completely wrong, and more likely that he is the one saying that various (naked) emperors have no clothes. I'm sure he's not always right, but much of what he says seems quite plausible to me (a fairly well-educated person with some understanding of statistics).
I'd love to know where folks have mounted successful critiques of his work, or if he has any conflicts of interest that he doesn't mention.
Let me introduce you to the "lab leak hypothesis", which was decried as racist for years by prominent Democrats and scientists. It lost this reputation around the time that another prominent liberal (Jon Stewart) saw fit to mock its detractors on national TV a while back. This was not firmly established science at first, but those on the left made impossible to even discuss in mixed company, which shut down the conversation and any rational investigations.
For other examples, check out Vinay Prasad's writings. He's a Bernie supporter, a UCSF professor, and the rare progressive who is willing to call out hypocrisy and graft even when it appears on the left.