Fantastic! On the other side it shows us just why so many purebloods fell into the trap of Voldemort. Think of the blow his pride had to have taken for Lucius Malfoy.
They join Voldemort in desperation and/or madness.
But like it was said, even if they had won and unleashed dementors werewolves and more onto the muggle world, what would have followed would have a bloodbath, only Voldemort with his horcuxes would have survived.