Because it's emblematic of laymen without understanding of medicine both demanding treatment with no evidence behind it and claiming the establishment NOT providing it is evidence of some vast, many-tentacled conspiracy.
However, one of your comments shows the true problem. It's not FOR the media to decide. Murdoch may disagree but the media is just reflecting the establishment. You can argue about the effectiveness of said establishments because they're all dysfunctional, like any organization of any size, but to claim that we should just throw away scientific process in anathema to modern society.
There were multiple reports of people refusing treatment (and, of course, vaccines before that) because they wanted ivermectin.
Prior to that, people poisoning themselves with household products due to Trump's careless speculation on treatment.
It's ironic as those who don't trust vaccines seem to flock to the medical advice of those without any training.
The backlash has never been primarily about the dangers of ivermectin specifically, but the rejection of established protocol, scientific procedure and basically everything that humanity has moved forward with in the past century or so.