I don't quite follow your reasoning here. It's got a really bad reputation with devs and people "in the know," but for the average user turning on the computer, it's perfectly fine, and that has to count for something.
That's the part I find interesting - despite being good enough for all the major sites on the internet, they kept bumping up against cases where it didn't work. But I don't understand why they needed a new browser to fix that; the article implies that all it required was a change in focus.
Exactly, this is the thing people keep forgetting. IE has a market for people who don't change the default browser from their computers, and it's a good thing they are getting a better, modern browser (not that IE11 is bad, mind you).