Even in the most civilized regions of the Nexus there are differences between sophonts which amount to one being in a state of relative poverty compared to others. This poverty can be the result of various factors.
Bad Management
Those who waste their resources — money — sooner or later go bankrupt, or whatever the equivalent is in the place they exist. This occurs a lot in the Terragen sphere, where so many utilities and luxuries are to be had. Raw Hedonism has been responsible for driving whole clades into abject misery. There's often a social net in place in most systems but with some the tendency to mess up again and again is as consistent as fungus in old habitats.
Isolation
Those who live in isolation have less access to resources of the centralized universe. The state of isolation isn't limited to remoteness, in a sense being physically very far removed from the central fount of wealth, resource, progress and information. It can also occur right next to the affluent, out of sheer belligerence, out of habit, chronic bad luck or similar reasons. One doesn't need to be eccentric in constitution or beliefs to be cut off from the flow of capital, ideas and evolution which is nearly universal in Civilized Galaxy.
In the back corridors of some old, semi-derelict habitats live virtuals, cyborgs, baselines, xenosophonts, provolves and everything in-between in a state of relative poverty. Most of them still have it better than even the most affluent of the early Information Age baselines, but they may also face challenges that are larger and more complex than those of the Information Age. The same occurs on out-of-the-way places on even the most civilized planets, where people have just fallen between the cracks. It may be oversimplistic uncharitable to just refer to these unfortunates as 10500 AT "sapientrash", but many do.
There are huge numbers of these beings, scurrying about their everyday existence, generally preoccupied in some manner with a distinct cycle of activity which has no meaning or significance to the rest of the Galaxy, but which has become a self-sustaining loop to them.
Ideology
The persistent, stubborn decision to refrain from taking part in the universal progress has always been a common one and is not necessarily limited to religious taboo or a luddite antipathy for one or more technological capabilities. Politics or the legacies of history can also play a dominant role in why sophonts, even the most subjectivist kind, can dismiss the use of a fundamental and otherwise rewarding resource. The resulting poverty and misery are taken for granted or often glorified as a symbolic token of moral character. The number of cults always travelling through a system in a state of visible anguish is a testament to the fact that this behaviour is all-too common in large parts of the Nexus. Colorful though this dogmatics can be, they are also pathetic - and they can be a nuisance when they insist on impressing the merits of their plight upon others less so inclined.
Eccentricity
Apart from a mental attitude limiting oneself (an ideology or dogma, or simply a lack of any focus at all) there's also the possibility that a sophont in the Nexus or anywhere in the Terragen sphere, is so intellectually off, strange or "lateral" in thought it cannot, by virtue of its identity or physique, immediately acquire or share in all the riches of the Terragen sphere. This occurs even in the wealthiest of systems anywhere.
Sometimes unbridled jealousy of the poor can keep them in their place; a jealous attitude running amok can result in defeatism. To some, the use of self-improvement is nil if they can't be top dogs or top of the food chain. No amount of effort will make any difference in their perspective. They will prefer to turn inwards, mope and ignore the outside universe altogether. With a little luck they will seek out their own world or solar system to mutter and complain but quite a percentage don't, and stay trapped in this psychological profile.
Curing Poverty
Sometimes available technology is so standardized or restricted it simply isn't directly accessible. A minority of xenosophonts or exotic tweaks in any given system may have radically different chemical compositions and may always be one step behind the rest in developing themselves. Also the locals may not be too keen on helping these or similar minorities from attaining the relative power they hold so dear.
Another problem is the issue of free will. Can one be forcibly "cured" from a negative lifestyle, without interfering with free will by rewriting of minds/attitudes/beliefs/memories via nanite psychoneuronal modification? Many in the Nexus of civilized systems think the answer to that is "no".
Articles
Alien Nation - Text by M. Alan Kazlev A rl or virtual ghetto of any group of outsiders or exotics whose memetotype, psychotype or phenotype does not match that of the majority, and hence have become socially stigmatized, either by their own choice (self-alienation or banding together for protection or social continuity) or by the decrees of the majority society. Most large and even some of the smaller polities have a few alien nations such as a penglaitown, a little centauri, a splice-quarter, a replicant-hive, a mandelmanode, or an exotics strip.
Crime - Text by Anders Sandberg Acts punishable by law, whether a violation of local regulations or of the sentient rights of another being. Crimes in the ultra-civilized systems of the Inner Sphere are in general very subtle - data manipulation, fraud, extortion with embarrassing information or purely software crimes like mind casinos. In the less regulated systems smuggling, theft and more property-related crimes start to appear, and out in the simpler regions traditional seediness and crimes are common.
Factotums - Text by Dagon Generic term for degenerate discarded, obsolete or homeless vecs or bots.
Interstellar Econometrics - Text by Anders Sandberg, with some material by HÃ¥kan Andersson Trade between distant worlds is made difficult by distance and the cost of interstellar transport.
Social Criminals - Text by M. Alan Kazlev, based on an original by Bob Black Generic term for those members of modosophont society, outcasts, drop-outs, the deviants, the dissidents, from every clade and race and sector of society, who are unable to find a place for themselves in the civilized galaxy.
Trophic Levels in Society - Text by Anders Sandberg As societies and civilisations become more complex, they develop trophic levels, defined by their distance from primary production.