The pursuit of happiness is nihilistic
A passive pursuit is not a pursuit at all.
All we need to do is examine the root cause, why do people pursue happiness? It's not by coincidence. People who pursue happiness pursue it because in childhood they did not have happiness. Happiness was lacking, therefore they believe the opposition, their pursuit of it, will resolve their childhood problems (in an irrationally subconscious way).
Another way to state this, is people don't pursue happiness if they believe themselves to already be completely satisfied. Pursuit of happiness can only happen if there is a lack. Where does that lack come from? From a childhood problem, namely not developing an affection towards any particular activity with commitment because of parental intervention.
Pursuing happiness will not resolve that childhood problem. Finding an activity to commit to will resolve that problem.
Lack of Self-Determination
The parent, owing to whatever reason, was not attentive to the kid's desires and instead transposed their desires on the kid. This usually takes the form of pushing the kid to try new activities, forcing them to adhere to activities they don't like, preparing them to be well-rounded by having a host of different extracurriculars, and not paying attention to what they actually enjoy doing.
The child fails to develop a sense of want because their wants fail to gain expression over the demands of the parent. They lose out on a sense of knowing what their desires are, and instead develop a "nothing-interests-me" attitude that then gravitates towards easy pleasures or occupation without effort. The K-12 system does little to help this as the kid has little choice in classes and is forced into subject material they do not care about, further confirming their belief that there is not much they enjoy.
In the absence of knowing what they want to do, the child develops a paralysis to life —their intellectual, emotional, and spiritual dimensions are not being filled with an activity, but dying does not seem like a painless experience so life continues on by default, moving them to still participate minimally in activities by necessity.
This forward movement may look like development from the external viewpoint, but internally the child knows they are only choosing cursory interests that will soon pass. The experiences don't root themselves in identity or commitment, they merely exist as particular activities that fill time.
Having given up on finding an eager want, the child drifts into an existential crisis that finds itself answered by "the pursuit of happiness". In other words, the pursuit of happiness arises from having given up on finding an interest with commitment.
A lack of activity is synonymous with symptoms of depression and philosophically speaking, connected to nihilism. Nihilists do nothing because nothing means anything or find everything permissible for the same reason, but by default doing nothing is more nihilistic since it's a default —requiring no activity. Since the child would be hard-pressed to admit depression, hedonism —which is synonymous with occupation or activity without effort, "killing time", finds expression as a way to avoid the acknowledgment of a lack of activity which would lead to depression.
The pursuit of happiness seems like a reason, but it is merely a surface illusion that guises the root cause underneath: the lack of activity, which finds itself mirroring nihilism. It is not a choice to pursue happiness, but rather a rationalization that surfaces in the absence of knowing what to do —the pursuit did not arise as an activity in this case, it is non-active, an occupation without effort, in which case it is a passive pursuit of happiness! a contradiction since pursuit implies activity. It is a ruse.
The solution to this apparent meaningless of life that evolves into a pursuit of happiness is to "return to childhood" and go through the exploration and trial necessary to arrive at an eager want. This will require a letting go of the rationality that first imposed the "pursuit of happiness" as the solution to an irrational problem —that of choosing a desire, and instead developing one's capacity for stillness which will naturally lead the mind towards areas of interest that will accumulate in finding an activity that provides the intellectual, emotional, and spiritual needs of the individual.
In other words, open up a space to allow for new feelings and desires to enter —remove happiness first, then allow —a process to arise.