Face it, Lorna, you're a softie.
But you're right, they just took the easy way out. Another bit of hack writing was the scene where Clara and the other three were fighting the cyborgs with swords. Everybody hacking and slashing away and no one got hurt. It was just a filler scene, broken into segments to give the Doctor time to finish whatever he was doing.
A much better made show (so far) is The Strain
. No romanticizing of vampires there.