The pharma companies logic is completely sound, except that only a fraction of their profits go to R&D. Most of it is used to benefit shareholders.
So, they're full of shit.

https://www.latimes.com/business/hiltzik/la-fi-hiltzik-gilead- profits-20171023-story.html

"
In 2016, the company reported profit of $13.5 billion. It spent $11 billion to repurchase its own shares, and about $2.5 billion on stock dividends. So the buybacks and dividends together came to $13.5 billion, in effect consuming 100% of the company’s profit.
"

for the tags

I hate Philly D. But I hate Hep C way, way more. I was a hospital volunteer for a bit and Hepatitis of all kinds were everywhere and a big deal, I think hep C is kind of creeping from prisons into more financially well-off populations which are vulnerable: e.g, seniors and better-off immuno-compromised folks.

It would be pretty easy to unleash an easily cured disease into a controlled population an immunize the outside, as a slower but less flashy alternative to Zyklon B. Just saying, I can’t be the only person to have made that observation.