Unfortunately I don’t think you understand what’s going on at the Cathedral of Our Lady of the Angels. I certainly did not until I attended several Masses there. For anyone to truly understand, they would have to attend a few liturgies there.
In the simplest terms, many cathedrals/churches are about being monumental and beautiful works in themselves. Their “ministry” is to show-off (and I mean this in a good way) on behalf of God.
The focus of the Cathedral or Our Lady of the Angels is not to look intrinsically beautiful but to facilitate and support the celebration of the Holy Sacrifice of the Mass in a truly wondrous way. When you go to a big Mass at the cathedral your focus is not on a beautiful building but on the Eucharist in a very stunning way. The building melts away. It becomes all about the Sacrifice of Jesus Christ to His Father.
The building’s designer knew what he was doing.
The architect did this through the exquisite use of geometry/space, lighting, sonic engineering, materials, etc. A prime example would be the ambulatory that people walk-up as they enter the cathedral. It truly does serve to isolate the cathedral from the noisy outside. It also gives the faithful a minute or two to leave the world behind and to focus their thoughts as they prepare for Mass.
Experiencing the cathedral gives insight as to why it looks like it does. Are there things I would change to suit my own personal taste? Sure, but there are also plenty of qualities that I would retain.
In the end you need to remember that you judgement of looking “awful” is based on your own personal taste and very little practical understanding of this specific structure.