The concept is appealing—it's essentially Plato's philosopher king. The BDFL can unstick decision making and ensure the project moves forward without having to litigate every decision in committee, they maintain context and vision throughout the life of the project, and because they're not accountable to anyone they can make the right call for the project rather than having to make complicated political trade-offs. It's all the perks of a monarchy.
Unfortunately, we've seen over and over again that the BDFL model also has all the problems of monarchy. If you get a good one it's the most effective form of government, but people are fickle things. Frequently we see things like this, where the BDFL turns out to have been malevolent after all or decided that they are the project and are entitled to the sole profit from it. WordPress comes to mind.
A good BDFL is worth keeping, but I think we'll find that drawing inspiration for our community structures from real-world democracies/republics will be more stable and reliable in the long term and more generalizable across new projects. Democracies aren't perfect, but by design they smooth out the variance of the individual humans in the community, giving you much more predictable results over time than monarchies do.