As with anything - what's the user need?
The vast majority of people don't seem fazed about their credit card company knowing they've bought a sex toy. Hell, if Amex offered double-cashback at PornHub I expect they'd be inundated.
For those which do want a bit more privacy, it's dead easy to buy a single-use gift card or cash card. Will that stop the police from tracing you? No, but it makes it harder for a company to build a profile or a spouse to snoop.
So you're left with things which are (rightly or wrongly) illegal. Or incredibly taboo.
Is there a huge market for those things? If so, what are the customer benefits of Monero against cash? Or barter? Or owing a favour?
How easy is it - for both sides - to get set up? I can check cash isn't forged to a high degree of accuracy very easily. How much hard work do I have to do for Monero? How much educating my customers do I have to do? If Monero is restricted to shady stuff - how much of a target am I painting on my back?
It's possible for a company to stimulate and create user need. But that's a lot harder than tapping in to a currently unsatisfied niche.