Miners operate on thin margins and are collectively shaken by a disruption in their profit model. Contentious forks are thr last thing they want. UASF won, because node runners kicked in their doors, holding a knife to the neck of their golden goose, saying "I'LL FUCKING DO IT".
Discussion
Such is my opinion.
I like this energy.
Honestly, I don't think most of the people running ShaolinFry's code knew exactly what kind of mutiny they were partaking in. There were some serious risks in threatening to fork. But it provided a real example of what timid little bitches miners can be. Being solely motivated by profit has its downsides.