Sorry for that joke; it was in jest. This must be something they either overlooked, or just didn't manage to resolve in an economically viable manner. Or, at least, not yet!
I must admit I don't shoot a lot of 120 and when I do, it doesn't involve any red windows, but I have on occasion used a camera with one and I'm aware of the issue you have with the poorly visible numbering. It can be really hard to read, especially if it's kind of dark/dim to begin with and/or that red window has a little grime on it.