It's because he's running as a republican, so his former associates are finding any angle they can to backstab him. They're saying it was illegitimate and insincere for him to run true crime segments on his show, because it's supposed to be about medical things, and he was just including them as sensationalist crap to attract viewers. He justified it by claiming the crime stories had a medical angle like DNA evidence in the case, but they say this is not enough to justify him using this sensationalist material.
I'm no fan of his, and I'm sure he is a RINO and a cuck, but these complaints are nonsense. If his daytime TV talk and variety show wanted to have periodic true crime segments, or any other topic he thought would attract viewers, I say it's fair game.