You’re absolutely brilliant (like Cloudflare), your goal does not seem evil (similar to that of Cloudflare), neither do the consequences of achieving it (somewhat less like Cloudflare), and you haven’t done outright evil things like patent clever but fundamentally simple tricks (have I mentioned I’m conflicted about Cloudflare?). And when all is said and done, you do have to pay your bills, and only you can say what works and what does not in that respect.
So I applaud you when you say, loudly and honestly, that the goal of your licensing model is to pay for the development by making yourself an essential part of it. I believe you when you say your work couldn’t exist otherwise. But my mental model of (dev– and knowledge-of-humankind–centric) open source (unlike that of user-centered free software) is that its very essence is the original developer making themselves unessential or at least not using legal threats to preserve their special position.
Thus I am explicitly not saying that your non-open-source approach is evil—that would be unjustified purism; morality judgments are difficult and best not employed as one-sided proclamations. I am not expecting that you will go home ashamed or mend your dastardly ways, because you have nothing to be ashamed of, your ways are not dastardly, and I have no idea how you could mend them and still survive. I am saying that your non-open-source approach disagrees with the very core of the open source idea as I best understand it, not on a purist technicality but in a fundamental way.
Bruce Perens co-founded the OSI. He seems to have given up on the idea of open source in the age of mainframe providers wielding armies of star programmers, and probably would not have any issue with your strategy. I am younger and have not given up yet, so I look upon your strategy with sadness and a longing for a better world.
Bruce Perens is much smarter than me in more ways than one.