If you show a nonprogrammer a screen which has a user interface that is 90% worse, they will think that the program is 90% worse.
I learned about the power of Aesthetic-Usability Effect the hard way.
In 2014, I went abroad for a summer course and participated in web app development competition. I focused on implementing AJAX to enable seamless interactions without requiring the page to reload every time a user performs an action.
At the end of it, my project was the only one with AJAX capabilities. It was a technological marvel. It lost to competitors who used a nice-looking CSS but loaded a page after every user action! Ugh!
Why? Because my project was ugly:
A real UI horror, isn’t it?
Poor visual design ruined project’s chances and AJAX functionality alone wasn’t enough to win the competition.
Aesthetically pleasing interfaces are worth the investment.