Timo, makes you wonder how many of those colonies are in fact penal colonies, in all but name?
It seems that colonists tend to found their settlements without government help - even their ships seem to be their own property. And once the colony is established, it isn't in any way monitored by the federal government (our TOS heroes typically arrive to investigate stuff after years of silence!), despite typically possessing independent starflight capabilities and thus not being anything like a secure prison...
In that sense, I fail to see parallels to the penal colony practices in the latter half of the second millennium here on Earth. Colonists leave on their own volition as far as we know, and the social pressures that expedite their departure are their own internal ones. After leaving, colonists are free to move, and importantly also free to cross-organize if they wish to - something the powers utilizing penal colonies on Earth would
never have allowed to happen.
What we know is that small individual colonies are not particularly diverse - which is no wonder because they tend to be of tribal size. We have no idea whether homeworlds or well-established larger colonies are diverse, because Star Trek does not take place at such locations (large = expensive to film!). Suppression of diversity is thus something of a weak hypothesis, supported only by the biased statements of some of the more extreme colonists.
Or, come to think of it, not even truly supported by those. Even the most counterculture colonial attempt we saw, in "Way to Eden", was not motivated by suppression, but by technophobia - Dr Sevrin was creating an interstellar branch office for his Flat Earth Society, not because his ideas were being shunned or his lifestyle restricted, but because he found Eden's climate nicer than Earth's for his allergies.
Unfortunately New Maoriland is atop a rich duranium deposit that the Cardassians want. The relocation of colonists occurs
I wonder... The idea of the DMZ, apparently established after TNG "Journey's End" showed that the original ideas of clean division and relocation didn't work, was that each world inside the DMZ would remain in the hands of its original owners. UFP colonies would remain UFP, Cardassian colonies would remain Cardassian, and supposedly any independent worlds would remain independent. So if Cardassians forcibly relocate anybody on a world that isn't a Cardassian colony, that's casus belli - Starfleet would come blazing in and bombard Cardassia Prime until they apologized and withdrew, not because the UFP cared about the colony, but because the UFP would care about the upholding of the treaty and the political reputation riding on that.
Are the Maori living on a Cardassian world, then, and agreeing to be subjects of the Cardassian Union and to obey its laws? That is, is the colony identical to Dorvan V from "Journey's End" and dissimilar from all the colonies shown in DS9?
That raises the question of whether any Maquis could operate from New Maoriland at all - Cardassians would have the legal right to do whatever they please to suppress them there, even if there were some DMZ limitations on what sort of armaments they could use for that. Would the Maquis Maori emigrate to continue their fight in the style of the DS9 Maquis, or would they mount local resistance on a world as tightly controlled by Cardassia as Bajor used to be?
I suspect, given their love for nature, and the extremely, necessarily waste-heat intensive nature of Fed technology, they've pared the maximum occupancy to three or four billion...
...Or less. One of the original TMP concepts was that San Francisco had been largely dismantled and returned to natural/parkland state due to reduced, de-urbanized population on Earth; the matte paintings instead eventually went the "big showy futuristic architecture" city model. But I could easily see the UFP exercising ridiculously strict population control, which would in turn allow them to make real estate as free as food, in accordance with their seeming political ideology.
These tribal colonies are probably a good example - or even a piece of proof - of space colonization not being a relief valve for overpopulation (and thus perhaps the overpopulation not existing), and of the colonists (and probably all future humans) having relatively little interest in filling the worlds they inhabit.
Timo Saloniemi