I can't speak for everyone, but the primary reason I remain unhappy despite having my basic needs cared for is Marxist alienation [1]. Put simply, as long as I remain a wage-slave for the bourgeoisie, I will not have the capacity for true happiness. But not to worry -- I have plans. Patience is key. Soon enough, I will liberate myself from wage labor. Part of what's so great about being a programmer is that the means of software production are relatively inexpensive, and indeed I already possess them. Wish me luck! :)

[1]: https://en.wikipedia.org/wiki/Marx%27s_theory_of_alienation