One thought, and I don't know if it's true or not, but it is a possibility for what is going on:

before her accident, terri and husband discussed what they would want to happen to them in the event of vegetablization and she stated adamently that she would rather die than go on living.

Husband is trying to carry out her wishes and won't let the parents have custody b/c he _knows_ what she would have wanted. You can't give someone leathal injection in Florida, so the only way for her to die is to stop giving her food. I'm going to doubt that she's in pain, b/c that would be all over the conservative media (i.e. fox news) if it were true. Assuming she can even still feel pain, she's probably being given morphine or the equivalent. Given the options, this is the only way she can die.

Personally, if it was death by starvation or being a vegetable, i would rather die. I will not be kept alive by machines when my mind is that gone.

I agree that it is possible he is an ass, but I also think it is possible that he loves her very much and is doing everything he can to follow through on what he knows she would want.

Just a thought.