It helps people who don't know JS code for JS. And it helps people like c# / java devs just writing code without learning more that typescript. This is very powerful but it also can lead to Enterprise-like code writing.
Re:Announcing TypeScript 1.6
by threatofrain on Wednesday September 16, 2015 @10:10PM
(#10231190)
TypeScript is a superset of EcmaScript, and adds nothing new except for types. Only exactly that.
If I was writing TypeScript, I'd be using functions and simple objects.