I agree with you in principle, ideally there should be no feature separation but supported versions. But given the current culture of even large profitable com

I agree with you in principle, ideally there should be no feature separation but supported versions. But given the current culture of even large profitable companies just using open source projects without giving back - see the HN story about Github and Redis - and let alone contributing but even giving credit, some open source companies have no way to earn any revenue. They may then have to resort to this to support their development which ultimately benefits all users. Nginx is a highly regarded, widely used and high performance web server. As a long time user I would not grudge them trying to make some money to support and improve the project. As is Haproxy. I think there is room to accommodate both models and we are just incredibly lucky to have 2 such high performance projects available as open source.