"It's ugly but it works", if you've interacted with a lot of backend engineers or their products well enough then you've either thought along the line of the quoted text above or someone has said something similar to you. Some of the most powerful applications on the planet don't have beautiful user interfaces, they cost a lot to purchase and maintain which makes the average person question why these products can't be made prettier.
The thing about these backend-heavy solutions is that they're primary designed by backend engineers, backend engineers aren't particular about pretty, they're all about reliability and productivity. Banks and a lot of delicate sectors operate on some rather unsightly software and that's because those software have proven to have little margin for error. An example of a backend-heavy app that we use is Zoom; they prioritize power and reliability over aesthetics.
It takes a lot of software engineering understanding to appreciate the beauty in backend-heavy applications. The amount of intellectual muscle required to pull it off, these software solutions are a testament to human innovation and ability to interact with the machine.