I think in that case, the answer is "too bad, so sad". The patent system shouldn't guarantee some kind of monetary reward. If it does, it sets up the wrong incentives.
Independent invention should be a sign that the idea isn't worth patenting, that it was "in the air" at the time.
The comment to which I responded seemed to take the view that spending a bunch of money on discovering or inventing something should more-or-less be automatically rewarded with at least a portion of the "intellectual property" rights. That's the concept I wanted to rebut.
I don't have facts at hand, but I imagine that like any other thing (starting a business, writing a book, creating an App) 99.9% of patents result in no monetary gain whatsoever. But if we're going to go all in on the property aspects of patents, then I think that morally and ethically, we have to give an independent inventor a share of the property. Anything else just looks arbitrary, and leads to disrespect of patents, "intellectual property" and The Law in general.
Independent invention should be a sign that the idea isn't worth patenting, that it was "in the air" at the time.