It really comes down to how much you trust people to find their own path.
That clearly depends on how old they are. Below 18, you are required to be in school and you are not allowed to work. After 65, you get to live off our national pension plan and get free health care.
The other thing that makes me cautious about the unconditional income approach is the handful of rich kids that I knew in High School in Austin, TX. They had everything they could possible want handed to them and were miserable. It was puzzling as hell.
FDR had a really big internal debate over this during the Great Depression. Read a little of the history of that era -- it is not an easy tradeoff.
Basically, I think that people are really good at finding their own paths. It's what people naturally do, providing that they aren't structurally prevented or disincentivised from doing so.
And yes, I've seen the miserable rich-kid phenomena first-hand, and agree with you that too much privilege can be a real handicap. That's why I think it's quite important that an unconditional basic income be genuinely basic: enough to survive on without any privation, but not enough to be decadent on.
I've found a neat mechanism for appropriately setting the level of a basic income: 50% of the mean individual income. Here in the UK, that would produce a basic income of roughly £12k/year -- a bit less than working a full-time job at minimum wage. Enough to live a fairly decent life in a (now) impoverished Welsh ex-mining village, or enough to barely scrape by with a bunch of flatmates in London. But not enough to be extravagant on, in either case.
The nice thing about pegging the amount of Unconditional Basic Income to the mean earned income is that it builds in an automatic self-correction mechanism. If too many people exit the workforce, the mean earned income would fall, and the UBI would fall exactly in sync with it. As the UBI falls, people would be increasingly incentivised to re-enter the workforce. As people re-enter the workforce and the mean income rises, UBI would increase along with the inevitable increases in inflation.
Your proposal would create a poverty trap in exactly the same way as the dole (in fact this is how the dole currently works in Britain -- you've just described something quite akin to the Workfare program, aka slavery for the wageless). Unconditional basic income is not like this at all. It isn't paying people to be idle: it's paying people no matter how much they earn. Because you can never lose your basic income, you are never disincentivised from working. Thus people can volunteer, raise children, care for elderly parents -- or work part-time, or full-time, or in whatever situation they prefer -- without ever losing their safety net. This allows for nire diverse forms of value-creation to be created than in the kind of micro-managed nanny-state that you describe.