Humans have all the food and basic needs and luxuries they could require, but they have to stay on earth to enjoy them.
The Federation doesn't prepare or support them to function in another society or place that requires currency, so basically they have to stay on earth.
That's good. Roddenberry's utopian 24th century humans, if they did represent canon ST, outsmarted themselves. They thought they were evolving beyond petty concerns but only succeeded in turning themselves into penniless serfs. And now they just want to escape.
Ironic--humans have all that they want, absolutely free, and yet deliberately flee from it, and choose life in a colony where they have to work, struggle and use money to live.
But if you watch some episodes of TNG and DS9, like the one where the woman runs a colony like a cult, it is there.
Of all the strange new worlds Star Trek explores, it's the non-capitalist future, without poverty, that people have the most trouble with.
And I don't really buy that whats objectionable is the lack of explanation. Its the boldness of saying humanity has to grow up to reach the stars. And that growing up means going beyond religion, nationalism, and capitalism.
What is more likely is a mass extinction, huge population loss, and crawl back out of another dark age. But I prefer Roddenberry's worst ideas to more of the same.
One thing I like is that Roddenberry focused on humans creating a much better society than modern times.
Most other sci fi shows almost always focus on the advanced technology and aliens.
I think what might get some fans is the preaching--some of it light, some heavy.
Like, there's no television-style entertainment in the 24th century because humans have outgrown such primitive habits.
Only later on in other the series, however, we start seeing exactly that, because you can only watch plays, ballets, violin concerts and poetry readings so much