The reason Angular has silent failure by default is because failure is designed to happen all the time - this means angular expressions can deal with data that hasn't arrived/hasn't been created yet.

This might sound like a bad thing, but it actually makes the page work without confusing the expression syntax with endless or statements.

That said, I do see your point - it's frustrating to find something not working due to a typo in an expression, with no errors to point it out. A halfway solution could be some kind of debug directive/tag that logs when an expression doesn't evaluate? Or perhaps something integrated into Angular Batarang? (https://chrome.google.com/webstore/detail/angularjs-batarang...)