Sadly, it is not that simple. E.g. if your boss wants to see the numbers, and the dark pattern performs better. Just yesterday we discussed how the 'business' trumps the 'user': https://news.ycombinator.com/item?id=38483181

Sometimes, measuring long-term effects might be an option, but that might also not help. I am still in favor of fighting for a good UX, but you should not categorize everybody as a horrible person who builds such crap (even though I want to too) ;-)