Money is part of it but I do believe it’s an ideology. You’ve long had the grifters and con artists selling snake oil and other flim flams, but the ideology here is why people buy in.

People have completely lost trust in authorities. In the US its current form really goes back to the Vietnam War and its destruction of Johnson’s great society project. But since then American culture has grown increasingly distrustful of the government and it’s been a major tool of the republican party (despite nixon) as a means to sway support for deregulation after the new deal era of the government actually radically improving lives. This has spread over to all institutions, especially medical ones. (Honorable mention to things like the tuskeegee syphilis experiment and the cia using vaccine programs to run DNA tests)

Grifters and quacks have encouraged it, but it’s reasonable that they’re distrustful, they’re questioning authority. It’s just that they’re doing it unreasonably and against overwhelming evidence. There’s a whole bunch of fallacies and fears as well as being sheltered from the reality of disease (then doubling down when facing it). But the ideology is crucial here