The basically socialist idealism inherent in TOS and the first 2 seasons of TNG were, I think, driven mostly by Gene Roddenberry. Once he left the show de-emphasized this aspect. It feels like the writers post-Roddenberry feel this society that doesn't have money or scarcity is too boring. They see the non-capitalist society as a bit of a chore to incorporate. Which shouldn't be surprising, as the people involved in the writing, development, and promotion of the show are all making well into 6 figures and have a vested interest in promoting capitalism. With the grittier, darker NuTrek they have more freedom to basically ignore the fundamental equality that is supposed to define human society in the 23rd/24th century.