If a vendor runs a website to sell their wares that happens to run on linux, then yes it's "easy" to make money on linux. If you are a developer trying to make money on some software you've created specifically for linux, then it's a different thing entirely.

Yes but for the single programmer working by himself or herself, its much more palatable to build an app for iOS / MacOS and monetize from it. I believe that is the direction of the parent comment that I replied to. Many things run on linux but they are also very big softwares run by large teams