Because you don't just will a bear sex scene into existence, that shit costs time and money and they did motion capture, you know what that shit costs? It's not Quentin fucking Tarantino just lingering on feet for a hand full of shots, the models, the rigging, the voice acting, and a million other things aren't just a throwaway thing. That shit's expensive. And ultimately fucking every last thing they do tends to go against total budget. Chris Roberts walking into the room telling his designer to make that pixel blue, not green went into the budget, not so much for the designer but you bet your ass he did bill for that at the time.
This is not a Bethesda game where some modder just spends ten thousand hours without pay to make a bear sex scene, this is in house.