They are trying to get maximum sales; cool things like mature story telling (alla witcher 2) and realistic levels of gore don't help sale games to parent's of kids.
It is possible to behead people in combat:
"Pier Gerlofs Donia is reputed to have wielded a Zweih?nder with such skill, strength and efficiency that he managed to behead multiple people with it in a single blow. The Zweih?nder ascribed to him is, as of 2008, on display in the Frisian museum. It has a length of 213 cm (84 in) and a weight of about 6.6 kg (14? lb).[2]"
People here just assume things without doing any research, based on their (lack of) knowledge in physics and mainly, lack of knowledge in history. Dismemberment is not that uncommon, specially if the attacker is on cavalry or using weapons such as greatswords (http://en.wikipedia....Zweih%C3%A4nder). In XVIII and XIX century there are many reports on post battles describing mutilated bodies.
The crappyness of the freemarket and the need of business for MAXIMUM SALES.
RPG=immersion
No dismemberment =wut? It's immersion breaking when you hit someone in the neck with a claymore and their head doesn't come off.
Because the maturity of the novels i've been reading lately and games like the Witcher 2 i really really hope skyrim doesn't feel like a kiddy game which is a fear that i am having, b/c if it does i don't think i can enjoy it. As of right now i can't bring myself to play through oblivions vanilla game because everything is so generic, toned down and obvoius.