That I have values and if I have values, then I have reasons to do things.
And no, it is not a fact that you value it because it tastes good. Ascribing 'good' to your perception of its taste and therefore deducing causality, is merely a further opinion. It doesn't follow that this is necessarily the reason you value it - many have valued what they do not like, such as Flagellants or extreme ascetics - unless you ascribe the slippery concept of some form of masochism or complex. Some have sought to destroy, as can even be seen in abusive relationships.
I guess I need to take it back one step further. I derive pleasure from things that taste good, and things that are pleasurable are desirable. Things can get complicated when you have to weigh one value against another, so there are times I won't eat chocolate ice cream because it would be more pleasurable not to. Flagellants derive pleasure from pleasing God, and that's what they feel they're accomplishing by whipping themselves. Some might actually have been masochists, some might have developed a taste for the the pain as a conditioned response to feeling the pain of being whipped and feeling the pleasure of pleasing God simultaneously.
ETA I read up a bit on them. It seems some were motivated by plague, droughts, famine, etc, and thought that by using penance they could relieve themselves of these maladies. So I guess I should mention that I forgot avoidance of suffering. Since Christianity promises rewards for the good people, and punishment for the bad people, I don't think any religious folks are going to be a good example of people who aren't motivated by pleasure and pain. I guess the Catholic Church finally disavowed them when they tried to claim that whipping yourself with them absolved you of sin.
Yes, yes, this is just a guess as to their motivations, they might be something different, but it seems the only reason anyone does anything is because of some pleasurable emotion. Feel free to point out an instance that someone is not motivated by it making them feel "good" though. Not necessarily physically good, but emotionally, or psychologically.
It cannot even be said really, that there is necessarily therefore purpose therein - for purpose lies in their ends, which if this is merely for the sake of some sensation, has purpose for you but none for me. Only if I ascribe your perceived value to it as well, does it become so. This illustrates the problem of the solopsistic nihilist quite clearly.
See, this is where you guys lose me. In the same sentence that you say there is purpose for me, you say there is no purpose. There is no overarching purpose for all people, so what? That doesn't mean purpose doesn't exist. It just means that it's created subjectively.
This is why we may call crimes senseless, for to us, they are. They would however, have value to their perpetrators which would be as legitimate as our own estimations thereof, without intersubjective values.
Whoever said there was no such thing as intersubjective values? I never claimed to be the only chocolate ice cream lover.
This is a bit of sophistry, as you are assuming Fairness to be a good basis on preference, to try and prove that subjective preference is applicable in this manner. Why not preference for violence or human sacrifice or racism? That certainly seemed to work for Sparta or Tenochtitlan or the Third Reich. Why is it a 'good' basis, when you are assuming on preference what to esteem as good? This is a Petitio Principii. Hence my initial point that to make such claims, you need to smuggle and obscure significant underlying metaphysical assumptions that you would render untenable.
Since "society" has a general definition of people living and working together, you already have a subjective preference built in, as opposed to someone preferring to live in the wilderness all alone. Like I said:
Whether it's a good basis for society or not depends on what the value is and what the goal of the society is.
Without fairness, people won't have an expectation that their subjective preferences will ever come about if they work together.
