Sex is a major part of life: and that's how I like my RPGs to be, a lifelike adventure that I can relate to, in all ways.
DA:O had a good amount of sexual material IMO.
The thing about nudity and sexuality is, that it is rarely (if ever?) implimented in an interesting way. If violence in games were all about watching cutscenes of digital creatures ripping each other heads off, that would be gratuitous and boring. But that's where most systemic focus is on... DnD origin is a wargame afterall, not datesim.
If one wants to make a detailed game about relationships and sex, then sure... I don't know if it would be my thing, but why not.
As it is however, romances in RPG feel to me gratuitous and at best unnecessary.