It really depends on what kind of systemic consequences you wish for. For example, it could argued that unconditional help to relatives (the feminine tendency 7wb5 describes) strengthens family and community bonds. On the other hand, it could be argued that unconditional bailouts teaches the wrong lessons and leads to more bad behavior not only in those who make bad choices but also in others who now conclude they can take extra risk since family members will have their back (moral hazard). Politically speaking, one can even argue whether risk or e.g. power structures would be or should be "socialized" this way. There are many moving parts here and one can rarely do just one thing.
I think you do see "a line" in both of your examples even if you don't like to see it: A comment that finally opened someone's eyes---perhaps to something obvious she should have accepted much sooner. That's a line. Or a situation where someone was too naive, didn't do their research, and risked overextending themselves... IOW they gambled. That's also a line.
One can metaphorically see this is as chess game. I'm a decent amateur and can typically see about 4 moves ahead. A noob will typically see 2 moves ahead. A club champion will see 5 or 6. It is interesting to play with both types(*). One is blind to anything beyond their move-horizon: As far as they're concerned what happens after that is random or unpredictable [to them]. It's good luck if it favors them and bad luck if it disfavors them. What is clear is that some people have a better understanding of what's going to happen a few moves later in the game than others. Here one can explicitly draw the line in terms of how many moves someone sees ahead.
(*) It's even more interesting to play with someone with the same horizon as one self. In that case, one can truly say that the outcome of the game is based on luck. In many games are played the win/lose ratio between two people with the same horizon should be 50/50. Whereas the odds of a game with different horizons will be greatly tilted towards the player with the greater ability to predict consequences.
What's interesting here is that people are often given good advice (although to be fair, sometimes they're also given bad advice) yet they choose to ignore it. There can be all kinds of reasons why they ignore it. Perhaps there's no reason at all. Perhaps they're stuck on some silly idea or detail that doesn't matter. The better player can likely point that out too.
Overall, this means that some people just play the game of life badly. Typically not because they're unlucky because luck has a way of cancelling itself out in good outcomes and bad outcomes over time ... but because they're adding, essentially "negative alpha" to their decisions.
In terms of actionable strategies to identify whether someone is unlucky or really just a "bad player", one can be inspired by Bayesian thinking in which probabilities start at 50% (benefit of the doubt) and gets updated for each incidence/piece of new information. I find if someone has achieved the position of being family or a friend they generally have provided a lot of such probability updates already. All this is basically summarizes in the idiom: fool me once, shame on you, follow me twice, shame on me. In conclusion it should eventually become clear what someone's decision skill is. In real life, people might be helped the first time ... but maybe not so much the ith or jth time.
I suppose one could also look at it in investment terms. It could be that what you're seeing really was a case of bad luck in which case "investing" in these people's future would be a good idea. OTOH, it could be that what you're seeing is the result of bad investing skill in which case helping out is more like throwing good money after bad.
Add: I should also point out that humans are strange in that some are bad players but are also willing to listen and learn. Over time these become good players. But some bad players do for whatever reason have no interest in listening or learning and so they remain bad players forever even though it's clear to everyone, often including themselves that they are bad players. I am not sure what creates this difference. I think it's related to the 10000 hour rule in that perhaps deliberate practice is required. Some people might go through life deliberately in what they reflect on their choices and if bad things happened they try to understand why. While others dismiss outcomes as fate or luck and so don't reflect at all.
