Take this for what it's worth, but virtually every example I see here is for applications that are
supported on Linux, but certainly not specifically
targeted towards Linux. Looking through the comments I see Jetbrains apps (which are built in Java and designed to be cross-platform), Steam, Sublime, Spotify, Dropbox, etc. I can guarantee all of those apps make the
vast majority of their money from paying Mac and Windows customers, and they either offer a Linux version because they can afford to for essentially developer goodwill, or there is an interoperability story (e.g. a Dropbox user may use Mac most of the time, but needs it to manage some shared storage on all of their machines, including some Linux ones). Perhaps one exception I could see to this is highly technical or engineering focused software (e.g. Matlab, CAD software), but that software is largely paid for by large organizations like companies and universities.
HN folks may not like to hear it, but in general your "average" Linux user makes the absolute worst software customer: they can get tons of stuff for free so there is a high bar when it comes to willingness to pay for non-free software, they have very high demands about how software should work, and they are most likely to run customer configurations on different combinations of hardware, making bugs more likely, and they are usually quickest to switch if something better comes along.
And by the way, calling someone a "bad customer" is not really a putdown; being highly discerning about where one spends their money is more of a compliment.