Given your verbiage, I'm not sure that we're capable of a rational conversation here. That said I will agree that when it comes to healthcare, and the pricing of drugs (and services) things get emotional and sticky quickly.
But to think that you'd be able to treat 40m patients is a lark.
That deal was approved in 2011. I can't find more recent numbers, but 6 years later that drug (PSI-7977, sofosbuvir) Gilead had treated 1.4 million patients. Assuming each paid $7-8k for the treatment (and all that money went back to the parent company), I'm not sure that's breaking even as the 11b is only the acquisition cost, not counting clinical trials, manufacturing, marketing, etc. I'm sure it continued to generate revenue, but there were certainly other compounds competing for that market share, including additional approaches within their own pipeline (based on the article). I do think there's a real question for many of these acquisitions - and this is absolutely not the only example - of simply paying too much or overvaluing the asset or the market.
But I think it's also true that in many cases the goal is not necessarily to even get back the entire cost of the development for the drug, as much as it is for particular companies to try and build a franchise in a particular disease area. Gilead has certainly done so with Hep C, BMS with multiple myeloma, etc.
This is also one of those drugs, given the cost, that really pulled in some questioning regarding public funding for the clinical trials which according to this article was around $60m.
As much hand-wringing as the industry has done over the past year(s) in anticipation of the Inflation Reduction Act, and how it impacts drug pricing, it's clear that change had to start somewhere.