I mean, they literally can't go there if they want to make enough money to justify the production costs. I really don't understand why they even included that as an option.
I'd assume that some people equate sex with intimacy. The more sex you see, the more intimate and sincere the relationship. Obviously that's not true, but some people will still follow the doctrine.
I wouldn't mind a sex scene like in Mass Effect 1 for a romantic scene. Since the Cyber-Punk theme has a backdrop of sex, I think one-night stands and prostitution would be in there. If that's the case, the scene should be more violent, lacking any sort of affection between the people involved and really shows that it's just a physical need being sated.