At least moderately advanced text editors often interoperate with symbols tables, so you can jump to a definition. But even with grep, you can usually do it in a way where you differentiate between definition and use. But I am not arguing that you should not use advanced tools if you like is, the deeper point is that you can always use advanced tools even with headers, but you can not go back in a language designed around advanced tools and work with simple tools. So it is strictly inferior IMHO to design a language around this additional cmplexity.
