The Myth: " Buffy was the one who said the relationship was
unhealthy. Spike didn't care if she was using him and encouraged
her to keep on doing it."
In OWMF, he tells her that she's just using him and he doesn't
want to play, and tells her to leave him alone until she's serious
about the 'ship.
In Gone, he tries to tell her that if he can't have all
of her, he'd rather not have just the sex, but she won't let him
finish the sentence.
He loves her so desperately that even abuse is better than nothing
from her. Which is not healthy, either. And you know what? She said
the relationship was unhealthy for HER. Whether it was unhealthy
for Spike didn't even enter into the equation.