There is a line you see quoted from time to time the ST:TMP novelization, which I understand Gene Roddenberry had a real hand in crafting.:

We are a highly conservative and strongly individualistic group. The old customs die hard with us. We submit ourselves to starship discipline because we know it is made necessary by the realities of deep-space exploration.

He seems to have struggled with what his vision for a future society would be, versus the realities of making a sellable media property in the late 20th century. He posits that our Starfleet friends are actually socially conservative space cowboys by the standards of the UFP, which makes it easier for the audience to identify with them without compromising the rest of his post-scarcity utopian vision (e.g. that same passage indicates that James Kirk was partially named after his mother's first "love instructor"). However, it also means we're seeing a bizarre subculture of quasi-exiled psychological luddites who take on the eldritch horrors of service in Starfleet in return for not being slapped down into conformity.

It's clearly not a guiding principle for how Starfleet is generally portrayed in ST media, but it's interesting to think of them in terms of being distinctly apart from the rest of humanity while dedicating themselves to protecting it and expanding its understanding of the universe.