Was a different business model from a different time, making money directly off of selling good developer tools. Even Apple and Microsoft charged for their development tools until relatively recently, I believe.
Now open source and vendor tools have completely won that space, and its only possible to profit from developer tools indirectly. So not just Delphi, but the entire associated business model has become irrelevant.
JetBrains makes the best developer tools I've used, and while they offer free, community licenses, their more advanced tools still require a paid subscription.
It comes to my mind Unity (game engine), they have a very good business model. Their offer a free version to anyone willing to try, and premium tiers for more serious developers or companies.
Now open source and vendor tools have completely won that space, and its only possible to profit from developer tools indirectly. So not just Delphi, but the entire associated business model has become irrelevant.