"Transpiler" is a subset of "compiler", so it can hardly be a demeaning term. A transpiler is simply a compiler that translates code from language A to language B where A and B have roughly the same abstraction level. It is true that CoffeeScript is slightly more abstract than JavaScript in a few features (although JavaScript's inheritance model is more abstract than CoffeeScript's classes, for example), but any difference in abstraction level is tiny compared to the difference between, say, C and assembly.