As someone that has used vue.js quite a bit in the past, I have to admit what you came up against is quite odd. It is a very minimal framework.

He might just be that kind of JS dev that really likes to build a webpack castle.

You know, if you can drop in a url to a cdn-distributed version of a JS, you'll instead rebuild the whole thing in webpack, babel, and several other things just to be able to type "import".