I have owned a large dominate breed dog for the last 20 years (obviously different actual dogs but the same breed) when all the XL bully stuff started I genuinely felt sorry for them. I absolutely blamed the owners for any attacks.
I decided to rescue one (grown up kids, large secure garden, extensive experience with large breed dogs)
Long story short is I gave this dog a great home. He was rarely left alone, walked for hours, fully registered, taken to run free fields, fed a raw diet. The only negative thing that happened was he got in two fights with my older dog. These fights were split up quickly with neither dog injured. We decided to keep the dogs apart to avoid any further fights until the XL could be neutered (vet wanted to wait until he was 18 months old before neutering) I loved this dog, he never once showed any aggression to people. One day he had just been out a long walk, on returning he managed to run through the door as the person walking him went through. He ran for my older dog and they started fighting, they were separated by a strong man, he put the XL bully into the garden to defuse the situation. As he closed the door, the XL bully jumped up and bit his arm twice, level 4 bites, which required hospital treatment as an outpatient for 3 weeks.
I had the dog pts the next day. It broke my heart and still causes me a lot of distress. People blame the owners (I did) but this dog wanted for nothing, he was loved, walked, cared for, trained etc.
The vet told us that this was the fourth XL bully that he has had to pts. All with similar stories to ours, he said “they’re all fine until they’re not” I have since done a lot of reading up on them, and although many of them will be fine, there is a significant number that are ticking time bombs and their strength and bite force obviously make them exceptionally dangerous.
To answer your question I rescued one because I felt sorry for them, and I believed that I had the experience and lifestyle to provide an excellent safe home. It was a very hard life lesson and I still contemplate if it was my fault and if I could have done things differently.