This, 100%. On top of the usual "chews up more memory for not that much more functionality" issue that's always the case, the initial release of UAC was *spectacularly* braindead, to the point where the simplest way to make Vista usable was to disable it entirely - and once that habit was ingrained in users, they persisted on down the line, even well into Win10's lifetime. Windows really did need improved security/ permissions features, but their rollout was such a bungle that we ended up with a world where millions of people ran *less* secure by choice, because it just wasn't worth the pain.