Proving if something is intrinsically value is almost impossible! I really don't think any arguments for it have actually proved anything. How do you place value that isn't instrumentally valuable without anyone to put that label on it. I like the Omega man example. Omega man and the other man are the last people on earth. The other guy puts Value on Omega man not as an instrument but he actually valued him as a person. When the other guy dies and Omega man does not put value on himself, is he actually intrinsically valuable? I believe that since he is living he has intrinsic value. So even though Omega man is a self loathing man, he is still valuable.