With the privacy, your wife or girlfriend will never know that you've purchase porn or do gambling, but for some people, privacy is the most important even for no reason. I personally will protect my privacy I don't know I just feel like that I will not upload my details to the internet ( which is scary ) I'm sick of with those who are using our details to make money even a bigger company, that's why I choose crypto for any online transaction.
I think sometimes privacy is wrongly associated with hiding what you want to do. Of course, those are the things that jump to mind regarding online privacy but the essence is really "what I do is my business and mine only". Privacy has quite a bit to do with the very ideals that accompanied Bitcoin. It meant to free people from the state, in terms of putting them in control of their money. But along with that, not having an intermediary control and monitor your funds, which is one of the key reasons users were advised never to use an address more than once.
Just because you don't want to share information about what you do with Bitcoin or how you use it, doesn't mean you're doing something illegal or deviant. It can be argued that privacy should be your duty, to limit power being concentrated in the hands of the few. Knowledge is power, after all. The more someone or something knows about you and others, the more power they have over you.