Microsoft has tried way too hard to improve Internet Explorer and their hard work has not paid off. Even to this day IE is slow and dated. It was good back in the day when it was the best and one of the only web browsers. But that ended around 5-10 years ago. No wonder Firefox and Chrome support Windows, LOL.
Yes removing IE would benefit Microsoft hugely. Who uses IE anymore anyways? You have so many other choices that are less buggy and run faster and are optimized to the hill. I use either firefox, Adavant, or Firefox or Google Chrome this all depends on what I need to do in the browser.
The removal of Internet Explorer would definitely be a big plus. If it isn't already too late, replacing Explorer with almost any of the new browsers would increase interest in a Microsoft Windows system. Internet Explorer has aggravated so many people with it's compatibility issues and inability to keep up. Combining Windows 8 with Internet Explorer was not a good move.
The removal of Internet Explorer from Windows in favor of superior Web browsers would generate additional sales for Microsoft's operating systems. This is because people would need to update ther systems and also perhaps get compatible components that work best with the newer web browser. Changes in technology always bring new profits.
The removal of Internet Explorer from Windows in favor of programs like Firefox and Crome would not generate additional sales for Microsoft's operating system because it is simply very easy for anyone to download (for free) the web browser that they like best and to delete Internet Explorer on their own.
I do not think that removing Internet Explorer from Windows in favor of superior Web browsers would generate addition sales of Microsoft's operating systems. I think that if such a thing were to happen, people would just resort to buying whatever they thought was decent. Microsoft's operating system wouldn't necessarily benefit from it.