[bigDinosaur]

The core of science is iteration based on experiment and hypothesis generation. The scientific approach to UX is simply a hypothesis that a UX change is superior, and an experiment with a measure as to whether or not this is true. Yes, of course you can optimise scientifically for user-antagonistic KPI's (no need to invoke Hume, his point is true and also useless) but the alternative to not adopting a scientific approach is literally just opinion which on the whole is far worse (would you want your airline cockpit's UX to be designed based on a designer's opinion, or real scientific approaches to how people process information and intuit controls?). Of course one would take a good designer's opinion over some MBA-ridden process but a good designer is likely intuiting what would be validated by a more scientific approach anyway.