I say that some who likes Jetbrains and buys their products:

No one in his right mind loves the UI of Jetbrains Apps and the Linux experience has always been a shitshow unless you were using Gnome or KDE. Because Swing does not implement the XWindows protocol properly. So yeah, a great team can still make a functional app with terrible GUI technology -- but there is a world of a difference to something that's really polished, fast and enjoyable to use.

I think IntelliJ has the best UI of all IDEs I've seen, it sure as hell beats Visual Studio (the paid one), it beats Netbeans, Eclipse.. What else?

VsCode and atom are simpler, but they just don't provide UI, for many setting you have to go to config files, and some functionality is missing outright.

Can you think of an IDE with better UX?

Jetbrains products are my preferred choice for full-featured IDEs, but this is not exactly an industry renowned for producing snappy and pleasing interfaces. And since LSP has narrowed the gap, most of the time I don't require the features that would make up for the bad UX so the majority of my coding happens outside an IDE.

MacVim is my favorite when it comes to UX. It starts instantly and stays fast even on huge files. It's very customizable and works exactly how I want, including the layout of nested horizontal and vertical split panes.

I like being able to configure just about everything in just a single config file, but still getting an additional escape hatch for overriding OS default keybindings I want to use.

People love IntelliJ despite Swing because its other qualities make up for the slightly off-looking Swing font rendering, the glitching Swing layout redrawing and the glitching Swing window focus.

Also, the menu bar in IntelliJ was reimplemented from scratch to make it work properly. The Swing menu bar would have been unusable with its broken handling of submenus.

But they're ugly and impossible to use, for some of us. Just awful and horrible UI and flow... I simply do not get the love for IntelliJ anything.

Agreed, the only thing going for IntelliJ is that its easier to use than Eclipse, but the product is still too complex and ugly.

Really? I love eclipse. Though not as much as I used to.

I suppose preferences here are at least partially determined by how you think about software project management. Eclipse makes perfect sense to me, and has since the first day I used it. IntelliJ is obtuse and odd and ... wrong to me.

I agree that Eclipse is better than IntelliJ, but is not as easy to use. But after you get used, Eclipse is a better product.