For years, Windows got laughed at by EVERYONE because there was so much malware on it - in part because of its laissez-faire approach to letting the user install anything from anywhere.
Mac went for the closed garden approach and there's hardly any malware, adware, scareware or whatever -ware you can think of on the platform, which is one of the reasons why Mac is safer and considered to have a better user experience.
Curation is not a bad thing. And if an open source application wants to become popular for the masses - not the HN power user crowd, which represents only a small percentage of potential customers - they have to conform to its rules.
Likewise, they will want to be available through the Windows store as well.
Using the tools and platforms offered by the OS developers is the lowest friction option for installing software.
As for poorer people and countries, isn't this where the open source charities come in? Isn't this where the big FAANGs - including Apple - and the investors and everyone that earned billions off of software should come in? I mean come on, it's only $99.