Developers spend hundreds of hours of their lives to learn these platforms. When that fee came out, many had to pivot, letting all that experience go to waste,

Developers spend hundreds of hours of their lives to learn these platforms. When that fee came out, many had to pivot, letting all that experience go to waste, and starting over in other platforms. It's hugely disruptive to their time, their careers, and income. Many have moved on. Dropping the fee doesn't mean they will come back. Even if it made financial / career sense, they were burned, still with a bad taste in their mouth from the experience. They cannot trust that Unity won't screw them over some other way in the future, better to keep going with their newfound direction if it's starting to pay off. When your users / developers lose trust in you, it's the beginning of the end.