I don't see why it would be called "comically bad" compared to its contemporaries. The 1.x series was a bit spartan, sure. But the UI itself afforded several unique features that weren't found anywhere else. The ability to have multiple "screens" or viewports with independent resolutions and color depths and drag them down to navigate between them seamlessly was quite useful, as was the ability to move windows on top/bottom of the stack without focusing the window (which is largely a forgotten paradigm, outside of forced "always on top" windows which is just a bandage over the lack of decoupled focus and window depth). AmigaOS certainly got better for the most part with the 2.x and 3.x series. Commodore's mismanagement is largely what did the Amiga in, not any technical aspects.
I only became an Amiga owner in the 21st century, when it was all over bar the shouting, but friends owned them at the time and loved them. (I had an Acorn Archimedes with RISC OS 2.)
As I understand it, the weird colours of AmigaDOS 1.x (blue, white, black and orange) were chosen to deliver usable contrast on an analogue TV set. This not only means a blurry CRT, but also that, given where the Amiga was designed and made, it was an NTSC TV.
They have a good excuse for it. They designed everything to look readable/usable on average home TV. Add the loss of quality in RF modulator and you figure the crazy colour scheme with ultra simple icons.