But it's dangerous to claim that all poor and even any significant percentage of poor people are poor due to their traits. It's not that having certain traits could bring them out of poverty but rather for the large majority the only difference between people who are rich and poor is luck, cards they were dealt.
If we assume people spend first on necessities and then on luxury, which is pretty reasonable assumption, then UBI would increase consumption of necessities far more. Which would cause inflation in prices of those things, but over long run the supply chain would adjust bringing the prices back to equilibrium.
Are there people who have no idea how to spend money, yes! Often this is just not poors but can be children of ultra rich, who never saw money as limited resource and by the third generation have squandered all of inherited wealth.
It's valid concern that inflation would destroy the middle class. But assuming inflation is end result isn't the full picture. More money => higher demand => higher prices => more profit => increase in supply => more supply => lower prices.
So over time prices come back down, perhaps not where they were before money supply increased but definitely not at peak.
With that said UBI for bottom 50% is going to become more and more required as digitization, automation, and AI makes it that few people can own entire industries.
There was a point where advances in tech would just mean new types of jobs but always more jobs... lost typewritters but gained more computer clerks. But now tech is at point where advances reduces total amount of jobs. Soon cab drivers, cashiers, pilots, teachers and much more is going to be replaced with technological solutions that scale without humans.
The trend would eventually lead to 60%+ being unemployable and you only need so many people to write code.
So yes i think post industrial society is flawed.
UBI would alleviate some pain and symptoms, even if there are bad actors.