One might argue that pleasure, and only pleasure, matters to us. If that were correct, we would have overwhelimg reason to want to be hooked up to a machine that would cause all our favorite sensations. Few people in actuality would want to be connected to said machine, an "Experience Machine".
Reasons for doing so (no wanting to be hooked up to the machine) might be:
their desire to act in a certain way
desire to be a certain sort of person
to be in contact with reality
a higher or supernatural being
there would be no limits we need to strain against or transcend, no progress to be made
'a few sour tastes make the sweet ones that much tastier'
What matters to people other than their experiences? Why wouldn't you be willing to hook yourselves up to an "Experience Machine"?