Because they think by doing something they can “achieve” or “unlock” a spiritual awakening. We are told by spiritual teachers that meditation is key to awakening over and over, so it must be true and we follow.
Mediation is certainly useful in slowing down a mind that for years jumps from this thought to that without any time to really observe what is really taking place. A quiet mind allows a seeing of what is as it is without trying to change anything. However, the act of meditation in order to get so-called “enlightenment” is a distraction for the seeker. The seeker believes the harder or better they meditate the closer to awakening they will get.
“Awakening” is more than likely to happen when one is not meditating at all. When the seeker is not actively seeking and just doing whatever without any thought about trying to get somewhere it is noticed that Everything Is as it Is and that’s that.
It is so simple the complicated mind cannot see it.