Yes, web developers are generally unfamiliar with shell interspersed with Make. Not wanting two additional languages for your project is an excellent reason to use a tool that matches the rest of your project.
Not wanting two additional languages for your project
is a very silly reason. A build system is a system and needs to be learnt, whether it's a library in JS or a domain-specific language.
(That a JS-based build system shares syntax with JS is not relevant, since the useful denotation is JS syntax->build script, not JS syntax->JS code (unless you're debugging the build system itself). I contend that the denotation JS syntax->build script is no easier, and is perhaps more difficult, to learn than the denotation build syntax->build script, as it is, by definition, confusingly similar to the syntax for JS code!)
> I contend that the denotation JS syntax->build script is no easier, and is perhaps more difficult, to learn than the denotation build syntax->build script, as it is, by definition, confusingly similar to the syntax for JS code!)
Really? gulp build step dependencies look almost exactly like AMD dependencies.
Edit: my wife has also asked me to ask you "will it scale?"
I've never used (or even heard of) gulp or AMD (I'm guessing they're widely used outside of JS-only environments), but from your statement I infer that one must be implemented as a JS library, and one must be a DSL with JS-like syntax.
Are you implying that my parenthetical is invalid because the DSL has JS-like syntax? You must have missed where I said "no easier" and "perhaps more difficult". If the DSL's syntax is identical to that of the library's, then clearly the denotation of the library is no easier to understand than that of the DSL – they are identical.
Any developer should know how to write basic shell scripts to glue things together. Not taking advantage of the excellent pre-existing unix systems tools is a huge mistake.
That becomes a problem if you also want to have your project to be buildable on Windows, and it seems silly to exclude one platform solely because your build process doesn't support it.
Your comment seems to imply judgement of web developers for not looking outside their community, but fragmentation seems part of the nature of the software community. Demographically speaking, web developers are more likely to be younger, have grown up with Windows, and to have not developed for a different platform. In that context it's not surprising there's lower than average familiarity with Make.
make isn't even that good a build system... any system that requires that you create your own "clean" step(s) is wrong IMHO. A good build system is aware of the intermediate and final artifacts produced and knows what artifacts need to be created when changes are made [0].
That being said, javascript build systems just repeat the mistakes made by make, instead of learning from those mistakes.