Using frameworks is totally mandatory in application industry.
When I hear people who develops apps with pure language or home made framework
(meaning bunch a code lines barely packaged and tested by one single personne on hearth)
I usually scream internally...
There are couple of scenario where it could make sens, but for the 9x% of time, avoiding them is madness.
So why some one would do such a thing ?
Learning a framework is a long process, especially if you are already struggling with language.
It's easier to copy paste stuff from the web in an unstructured project (yes, i'm speaking to you, pseudo-PHP developer!).
Also, framework learning is Top-Down. You start with advanced interfaces built on the top of smaller gears that you'll discover later on.
This does not feat every body's mind.
And recently I faced the frustration of using a framework.
I wanted to implement a file upload on an AngularJS app, and I spent way too much time on it.
I give you the solution I found and some tips around framework usage: