With FOSS software, an enterprising and capable individual always has the ability to modify/update/or other wise change the software to suit their needs.
I find your line of thought to hold little weight.
Sure, and the parent I was replying to said he is happy to pay money for software he uses. I don't see why paying for closed source software (to encourage the dev to keep developing it and also to allow you to comment on what to improve) is a bad thing just because the project is not open-source.