Why is that? Transpiled ES6 code will stop needing the transpiler once ES6 launches. Typescript based code on the other hand will need, well, Typescript forever. If you're willing to stray out of standardized JS territory, there are plenty of other languages available.
Why not Typescript? To many, it's better than Dart, not as volatile as the ES6 draft and not as seemingly illogical as Coffeescript.
Plus, it comes from Microsoft and there are literally millions of devs out there who only want to use what Microsoft is pushing because they know that if Microsoft gets it right, they will reap the benefits of robust hiqh-quality tools and components as history has shown them. So far it looks to a lot of us like they're getting it right.
There's obviously no true measuring stick here. If you don't like Microsoft's style, which I'm betting most folks here don't, then it's probably not for you.
I think that "better than Dart" is an opinion that is not shared by everyone. Personally I think Dart is better but also more different than javascript which makes it a bit harder to learn. As you said, a lot of developers on the MS stack likes to use what MS builds but others prefer things not from MS (sometimes very stubbornly :-) ).
Exactly. Silverlight was awesome! It's the best cross platform UI kit I've seen yet.
It's sad that the trifecta of lame known as HTML/CSS/JS won out due to the fact that it's the only cross platform kit that native mobile environments will fully support, since it's so non-threatening.