Interesting--I've never in my career actually seen a user study or focus group that concluded that users don't like dense UIs or lots of options. Not saying they don't exist--sounds like you experienced a group that found this. I've just never seen it myself.

What I see a lot is UI professionals and artists simply declaring that interfaces must be minimal and abstract and that visual complexity is bad. Whether this is just current fashionable dogma, or if there is actually research to support this, I have no idea, but none of the product decision makers I've worked with have ever asked for evidence.

Ed Tufte makes the point in his lecture that the sports pages in the newspaper and the stock pages contain loads of many tiny detailed numerical statements. Newspapers are generally written for median intelligence people.

People don't verbalise enthusiasm for lack of busy UI, but they tend to prefer simpler UIs especially if they are not expert users of a more complex UI. It just looks cleaner and less stressful. The choice is expressed through usage rather than studies.

It was something of a unique audience, as these folks were not computer literate and we were training them to be machine operators. On the professional software side of things the big dense UIs seem to be holding their own, so they must have some good :)

I'm not sure screen density is a flaw in the Windows UX/UI style.

A lot of Windows programs have really cluttered, disorganized configuration menus and confusing workflows; PuTTY and ConEmu are two particularly egregious offenders. Seems more like a "developer lacking good design sense" issue, rather than something inherent to the Windows environment.