But having an application which is 100% HTML/JS/CSS/Interest other scripting language here. Without any ability to opcache or byte code it and encrypt it. It's not going to take much to crack it.
If they somehow found a way to compress+encrypt the HTML/JS they may be able to make it at least a little bit more challenging. But that would take a lot of effort.
Minification and obfuscation are quite common for web apps already. It's done for current phone apps, and it will be done for the new breed of web apps in just the same way.
You think bytecode is difficult to crack? :-)
One thing you can do is compile your JavaScript code to asm.js. That is low level enough to make things pretty difficult to reverse.
Until Hex-Rays Decompiler for asm.js comes out of course :-)