I don't mean this to be a personal attack, so please don't take it that way, but comments like this read to me as being written by a young, inexperienced programmer. I happen to know that this is not your case, but without checking the username, I would immediately classify this comment as such.
The people over at Microsoft are not idiots - even though Microsoft is no longer the new hotness, they still pay developers well, and have some pretty tight engineering going on. So when you say "The Event constructor is broken out of the box", my first instinct is to assume that the Microsoft engineers have implemented the constructor in their way for reasons that you're not smart enough to have grasped.
But, as I said, I know that you aren't a young inexperienced programmer, so you probably have some good reasons to make the claim, which leads me to the point of this rambling post - why is the Event constructor broken in IE? I'm curious to know what specific problems you have with it.
Sorry, I didn't provide details because I probably just assume everyone here is a JS developer, which is probably a bad idea.
IE11 has no CustomEvent constructor. You have to polyfill it with https://developer.mozilla.org/en/docs/Web/API/CustomEvent.
Microsoft's official Twitter account @iedevchat has pointed people to the same one: note the article article says for IE10, but the issue and fix is required for IE11.
It's a simple fix, but CustomEvent is ancient, and it's surprising what didn't make it into IE11.
The people over at Microsoft are not idiots - even though Microsoft is no longer the new hotness, they still pay developers well, and have some pretty tight engineering going on. So when you say "The Event constructor is broken out of the box", my first instinct is to assume that the Microsoft engineers have implemented the constructor in their way for reasons that you're not smart enough to have grasped.
But, as I said, I know that you aren't a young inexperienced programmer, so you probably have some good reasons to make the claim, which leads me to the point of this rambling post - why is the Event constructor broken in IE? I'm curious to know what specific problems you have with it.