This comment, copied and pasted from Jeffrey Strahl is directly on point as to why:

There is a celebrity from “the health freedom movement” who is currently running for the US presidency, RFK Jr. He has fully accepted the narrative summarized by “Pandemic”/“COVID-19”/“SARS-CoV-2.” This requires asserting that each of these three features has been proven. If a presidential candidate accepts this, s/he necessarily has to put forth some sort of solution for such a situation. A solution for a problem which doesn’t exist is an abomination.

Furthermore, RFK Jr. is pushing the idea of “lab leak bio weapon” from a China lab, meaning he accepts the existence of viruses as fact and of contagion theory as fact. This is utter disinformation, not a non-binary subject, and acceptance of it is absolutely unacceptable to me. The same can be said of “celebrities” who are pushing his candidacy, people like Celia Farber, Mark Crispin Miller, Jon Rappoport and CJ Hopkins. Corbett is free to be friends and in contact with whomever he wants. But i will reject any attempt by him to place RFK Jr and his supporters out of the range of criticisms, even trenchant ones. Policy choices pushed in public have consequences, including unrelenting critiques.