It doesn't make any sense from my perspective as a JS developer to steal code. Each JS code is tailored to fit the website particular HTML and CSS structure. Unless it's a jQuery plug-in or something in these lines.
If the developer doesn't put the comments, it'll be a hell more difficult to find out how to use the code and what the code actually does.
At the end of the journey, it's not these lines of code that make a difference for my client website. It's the solution I bring.
A lot of javascript code doesn't have anything to do with the DOM. Not just jQuery plugins. See underscore.js and backbone.js and handlebars.js for example.
If the developer doesn't put the comments, it'll be a hell more difficult to find out how to use the code and what the code actually does.
At the end of the journey, it's not these lines of code that make a difference for my client website. It's the solution I bring.