[imtringued]

You are assuming that the "creator" of the project has not contributed a significant part of the code base. If the commercialisation scares away developers that might be sad but that may not matter in the long run because core developers usually contribute the vast majority of the code. Drive by commits/pull requests could be still worth it, because it is the responsibility of the core team to carry the maintenance burden of your patch, so depending on how valuable you consider the time spent on your patch and how valuable you consider avoiding the burden of maintaining a fork, you may decide to simply donate your patch. If you wanted to be a significant contributor with no expectation of compensation, then this arrangement is suboptimal but if you insisted, nothing stops you from forking the project and taking it the direction you want.

A big problem with capitalism and economics is that all of it is seen through rose tinted glasses. In the mathematical models, everything you have said is perfectly accounted for, every single commit gets properly compensated down to the cent and even the companies pay exactly as much money as it costs the developers to maintain the software to the necessary standard.