Thanks for reminding me of that detail, Menu. Theorizing on the spot, I suppose he was reflecting on how he himself got out of poverty, which was by dint of devouring every book he could get his hands on, and not consigning himself to the low station in life his profligate father left him in (working in his uncle's factory putting labels on shoe polish at the age of twelve). Certainly his own father was "ignorant" in the sense that he didn't know the value of money, and never learned anything about how to handle money, not until the day he died.
According to the story the boy symbolizing "Ignorance" has "doom" "written on his forehead" which implies you are not doomed, poor as you may be, so long as you are not content to be ignorant.
This was also the philosophy of Dickens's contemporary, Samuel Smiles, a philanthropist in the tradition of Cobbett: dedicated, but highly patrician towards those he was helping.
Dickens might be criticized for only wanting to help people who were down on their luck, but extraordinary, like himself. But in those days, the extent of poverty in society was so overwhelming that Dickens's portrayal of intelligent, sympathetic working class people, far less ignorant than the schoolmasters and petit-bourgeoise merchants who earned far more than them, was a breakthrough for working class self-respect, and his works chimed with huge numbers of working class people, who adored Dickens and could relate to his petit-bourgeois background and work ethic - far better than they could relate to the "comedy of manners" genre of novel that had come before him, and which had reflected a mainly upper-middle-class social milieu.