This is utter tosh. If they do the thing you want them to do, than logic dictates nothing about their preferences at all. If changing the UX results in a signi

This is utter tosh. If they do the thing you want them to do, than logic dictates nothing about their preferences at all. If changing the UX results in a significant change in behavior, that actually suggests--I mean, "logic dictates" you've taken away an option that a significant number of people preferred so much they used it when it was available. Think about it this way: Given the choice of watching channel A or channel B or turning off the TV, I choose turning off the TV. If you take away that choice, I'll choose the lesser of the two remaining evils. That does not mean I prefer not having the choice to turn off the TV. Post-facto rationalization is just that. Users are not expressing a preference for dark patterns.