I already met many investors and millionaire founders. I even met 2 founders who are now billionaires and many others who went on to become multimillionaires. Nowadays most of them won't even answer my emails. One of the founders I met before they were successful (and who sold their startup for millions) won't even give me a $2000 per year support contract though they continue to use my open source project and ask me questions. I'm thinking I've been blacklisted. It doesn't make sense right?

Does it make sense that someone I met 10 years ago, was using my open source project as part of their startup and was having conversations with me every couple of months throughout the whole 10 years (they even let me log into their production system with 30K concurrent users to help fix a bug) and then went on to make millions won't even support my project with a $2000 a year contract?

Probably something weird going on. This is not just about one example, it's every now-successful founder I've ever met. Nobody talks to me and I did nothing wrong except build some products that work really well.