To be honest, for some of them it is a matter of 'preserving culture' and I don't think they would accept a 'higher' caste one either. That said, it may be different in other parts of India.
that's actually true, but in most cases, while they might be reluctantly willing to accept a partner from a "higher caste" they'd be downright aggressively dismissive of the other. And this holds for families all along the long chain of the caste hierarchy. Hypocrisy is a way of life.