Meaningful work should be one of life's prizes. Imagine working not (just) because you need the money but because you are passionate about what you do. You find your work interesting, challenging; you like that you get to use your skills, solve problems, learn things, and maybe even help other people.
If you are married and you feel that way about your work, you are probably admired for it. If you are single, there is some risk that you will instead be pitied. The attitude sometimes is (toward women, especially) that you don't "really" love what you do - you are just telling yourself that. Or you are compensating for not having what is truly important in life - a spouse.
What if we could assess people's attitudes toward work before marrying becomes much of an issue - for example, when they are adolescents, still in high school? It has been done.
In 1991, 709 Minnesota high school seniors (none married, none who were parents) were asked what would be important to them when looking for work. The two main categories that were assessed were intrinsic rewards and extrinsic ones. The extrinsically motivated adolescents cared mostly about how much they would get paid, whether the work would be steady, and whether there would be opportunities for advancement. Intrinsically motivated adolescents wanted the work to be meaningful - challenging, interesting, and full of opportunities to learn, to use skills, be responsible, and solve problems.
Nine years later, when those participants were 26 or 27 years old, the adolescents who had said they were looking for secure jobs with good pay were more likely to be married (and to be parents). Those who were more interested in meaningful work were more likely to be single (and they were less likely to have kids).
At ages 26 or 27, the participants were asked once again to indicate what was important to them about their work. Those who were married valued meaningful work less than single men and women did. So the study documented two consistent links between intrinsic motivation and marital status. Those who valued meaningful work when they were in high school were more likely to be single 9 years later. Even taking that into account, those who married were less likely to value meaningful work when they were 26 or 27 years old than those who were single.
The implications of being a parent by age 26 or 27 were more complex. For example, married mothers cared less about extrinsic motivations such as pay, whereas single mothers cared more. Fathers cared more about meaningful work only if they were cohabiting (and not married). As is typical for good research, other factors (such as level of education, current employment status, and income level) were ruled out as explanations of the results.
I'll add my usual disclaimer that social science studies tell us about trends, and not about what happens in every individual life. There are always plenty of exceptions. Also, the study I'm discussing does not say that you need to choose between meaningful work and marriage. Instead, I think it suggests that many singles who say that they care about the quality of their work experiences really mean it. They always have, at least as far back as high school.