Windows Forms in not cross-platform. The VS UI to build it is great, but the end result looks dated and only works on Windows.

I say the two are comparable because, with talent applied, the HTML version looks better and works everywhere, so there's a net win for devs that embrace web.

I don't understand why people are so concerned with looks when the result from the alternative FEELS so bad.

So you agree with me, the current state of UI development for the web requires more tools that makes you doubt about the best option for development. I only mentioned VS as a clear example of a good design tool but QT also has an alternative.