Don’t get me wrong, I understand the developer view-point. I really do. It’s an easy way to build a sustainable business.
However, it’s highly unsustainable for the enduser. We all have a limited budget. We can’t afford to pay for every software that way or we’d be broke.
Again, this subscription model is “unpopular” because it’s unsustainable for the endusers.
And people will find alternatives. iA Writer is pretty good too.
Consider this: Sketch is vital to my daily work. All designers use it, I need to be able to read Sketch files, therefore I have to have a license. Ulysses is just a glorified text editor. Yes, it has nice features, but the competition in this area is fierce, and markdown files can be opened and modified by any text editor. Why would I pay for a perpetual license for a text editor?