It's more like someone at some point stops being open to change, which allows some breathing room, but eventually they'll prefer to stick to what they know rather than having to learn something new. This isn't a value judgement, just that when something works and feels right to someone why would they feel the need to try something else just for the sake of trying it?
I use vim. Most people don't and would argue it's bad user experience as it's not intuitive. What's intuitive for text editing is largely just based on convention, though. I think vim is a great user experience because it allows me to edit text much more efficiently. It's entirely possible the text editor Kakoune would be even better than vim at doing the whole modal editor thing, but I do not care to find out. It took me some time to learn and get comfortable with vim and I don't see much value in going with the new thing even if it potentially has real upsides.
When it comes to UX/UI design, you'll certainly find plenty of conventions that are broadly agreed upon. Most people would find it difficult to read yellow text on a white background for example so that would be considered bad UI. But in the case of GUI design like determining how much shadow there is beneath a 'button' element or what color links should be and if that color is distinguishable is pretty subjective and a part of that comes down to convention rather than an innate preference in humans.