I am wondering if it is reasonable to write closed source, paid web apps in Javascript (JS MVC Frameworks like AngularJS, Backbone, Knockout, ...)? I'm concerned because in this type of frameworks you use typically a REST backend for CRUD operations and the majority of business and application logic happens in Javascript which can be looked up by anyone using my app. He can see how i do things.
When I use for example PHP or Java (Wicket) most of the logic is happening on the server and so a lot less of my source code is exposed. This seems to me a lot safer if I want to have an edge over my competitors, so potentially I earn more money.
So is it reasonable to use JavaScript MVC Frameworks for paid applications? Does it depend on something and if yes on what?