The 3.x and 4.x javascript api's and their use of dojo loader plugins lock developers into using the dojo loader and the legacy dojo build system - or it places the burden on the developer to create custom module loader implementations. I would like to see esri support the interoperability of module loading moving forward so developers can use modern loading/build/bundling tools with the 4.x api's without a lot of friction.
If this idea is accepted, developers cannot complain about the implementation details of the javascript api leaking into their workflows/technology decisions. The esri technology decisions of the api will be an implementation detail instead of an influence.