I must say I find it very hard to wrap my head around that you would say that the creation of a medicine to cure a real disease is not a work of value.
But there is value for him as he would have quick access to medicine if he ever gets AIDS. Of course someone who as AIDS values the medicine more but saying there is no value for him seems very short sighted.
The point is, everyone cannot be working on creating AIDS medicine. Someone has to be working on things that, say, cheer up the person working on aids medicine when she hits a wall.
Sure but these all have values then. His point was to show that AIDS medicine has no value for him, but it actually does. He can't use that argument to prove that value is subjective considering that it actually does have value for everyone.
