I guess they didn't want 'Adult mode' or whatever.
Also, DA:I, and even DA:O's romances weren't a given. I think there was only 1 'press A to have sex' option in DA:O and that was quest related. But otherwise, was a lot of relationship building that was involved in those games.
If you want a 'Press A to have sex' game, go play God of War. In the first game, in the very first level you can do this an unlimited number of times!