It's a dependency graph. It's just a data structure. You can do that in any language. Saying you need automake for a build system, or would gain anything from doing so compared to a native system, is akin to saying you need another language for arrays.
Regarding your popularity argument: amongst other JS developers you'd get more network effect from gulp. If your backend is, say, Python or Ruby learning automake wouldn't help you there either.
The point is that shell is not "another language", it's a foundation of the entire world of modern programming, not some esoteric thing for a single purpose.
It's a shaky foundation typically based on scraping text. 'its important and popular' is not a significant reason to add a language (or two in this case) to a project.
Regarding your popularity argument: amongst other JS developers you'd get more network effect from gulp. If your backend is, say, Python or Ruby learning automake wouldn't help you there either.