I think the difference is that you're using the language as a prototyping/design language: there, shortening the feedback loop is absolutely critical. There are

I think the difference is that you're using the language as a prototyping/design language: there, shortening the feedback loop is absolutely critical. There are lots of things that are not prototyping though - when I touch a graphical project I typically am working from a diagram that specifies all the color values and has a layout labeled with dimensions. For a contrast, I don't notice compile times at all in just about any language for the most part: when you reach the "few million lines of code" size, there's no language that is going to be instant; and for embedded/systems work, committing a change can involve things like creating builds for N different architectures and running a test suite that may have to control hardware [run times of the test suite are measured in hours to days]. At this scale, anything that the compiler catches, even if it takes an hour to compile, saves an order of magnitude more time later in the process. It's legitimately a hard problem to design a language that works well for both projects in the few tens of thousands of lines of code size -- i.e. tossing together a quick prototype -- and scales to millions of lines of code or larger.