As a D user... An IDE that works amazingly well, autocompletes everything and can refactor everything across many files (D will never get there because it make

As a D user... An IDE that works amazingly well, autocompletes everything and can refactor everything across many files (D will never get there because it makes heavy use of code generation). A much more stable and battletested compiler and a surrounding ecosystem. Wealth of libraries for each task, from game to web development. A lot of work opportunities in C#, not as many in D. Because of popularity, it's easier to attract other developers to your project.