Evolutionary signals are useful inasmuch as they retain the same context as they had in the evolutionary environment. In other words we're adaptation executors instead of fitness maximizers.
Our evolutionarily derived pleasure and pain signals are still useful even if they are noisy. They remain useful because the noise is systemic and can be compensated for. Eg, we loved calories back then because they were scarce then but they aren't now; we can note this and compensate. However, we still live a ~20% oxygen environment and going without breathing is bad for us, so we should listen to our lung's signals when they tell us to breathe.
I posted recently that "I tend to assume that things people hate are bad for them. CR may be an exception, but it's plausible that evolution would usually select for warnings that one is hurting oneself."
I think this points at an interesting question. If you know that people like a behavior, or dislike it, or love it, or hate it, does this tell you anything about whether the behavior is useful?
I expect that most people reading this question have a handy list-- one that comes quickly to mind-- of things which are good for people but that they resist. There's a tremendous amount in the culture (and perhaps more from somewhat different angles at LW) about people's reflexive preferences being wrong.
However, there's a lot where people's preferences are assumed to be in line with what's good for them that doesn't get much attention. I believe this is because there's a fascination with the drama of self-denial, but that might be a topic for a different post.
For example, people hate long commutes. I've never heard anyone say that long commutes are good for people.
People generally dislike being low on sleep.
Rather few modern people think that liking sex is a problem in itself. (Note a cultural shift-- anxiety about pleasure has been moved from sex to food.)
Nobody says that human contact is bad, even though many people like it.
And there's no cultural consensus that hating spam is bad, even though hating spam is a spontaneous response.
It's implausible that evolutionarily developed pleasure and pain should be completely out of line with well-being. On the other hand, it's a noisy signal. Should it be taken at all seriously?