I certainly think developers should be involved in UI design, but I don't think they should be the main decision makers in most cases, precisely because "putting both a really clever design and a really stupid user into your head at the same time is very challenging," and I wouldn't expect it to necessarily correlate with programming skill.
Not saying you can't employ a UI designer who does this full-time, but the final software product and the entire experience around it is still the developer's full responsibility. With this in mind, perhaps we'd like the developers to be more involved with UI design meetings?
All of this gets me back to the front-end/back-end meme that seems to have emerged over the last decade. Same sort of problem. All you do with this "not my problem" game is make your own life harder the next iteration.
So to be clear - I am not saying you have to do the whole product yourself, but I am saying that you need to care enough about it or it's going to turn out like shit. Writing software that people use is still decidedly an art form. Imagine paying to go to an art gallery filled with pieces created by artists who absolutely hate to make art.
The developer is not.
What is programming skill? For loops and writing a recusion function?
If you ever talk to a lawyer, they're not just robots that regurgitate the law, they can can give you good advice on mediation, and alternative means of resolving conflict. They'll aks you things like "are you sure you want to go through this, this is what this entails, etc." They don't just go "I only the know the law, I don't have a background in pschology, anthropology, sociology".
If you're a salesperson, you should know something about the product you're selling and have some communication skills. They don't just go "I am only here to show you to the car we're selling, I don't have a communications degree, I don't know how to offer you a deal".
Sometimes it feels like only in software are people so coddled that they think this stuff is normal. People will hire with leetcode as a strong signal and have stack ranking, and then somehow think that the streotypes of devs only being goot at logic puzzles and lacking human understanding are true.