Stop advertising the NSA please
Try-catch jungle, ad-hoc URL manipulation, lack of caching, writing/constructing HTML in strange places, weak comparison operators in dangerous places (string vs lunch), etc.
To be fair asking them to build apps that don't require JS is like the old man yelling to get off their lawn :)
It's hard maintaining two ways of doing things and it's not always easy to make them both use the same avenue. I'm getting to the point where I honestly don't care either way.
if (!undeclaredVariable) { var undeclaredVariable = false; }