It was Tom that was the problem, not the house he was in.

I agree, given the right circumstances, he might have turned out all right, but from the moment he was born he was doomed. As a child, he actively hurt the other children at the orphanage, to the point where two of them were never quite the same afterwards and everyone else was afraid of him. He kept trophies, too - at age eleven!

But he still could have been saved at Hogwarts - if the wizarding community had realized his home life was poor, and had a system in place for orphaned or unwanted magical children, and he'd been taken in by a family like the Weasleys. He could have been taught proper right and wrong, and perhaps he could have been saved.

Tom hunted for his father everywhere in that school for years, assuming that he was the magical one because he believed that had his mother been magical, she could have saved herself. He only looked for Marvolo once he'd been unable to find any Tom Riddle in any records, finding Marvolo Gaunt and his son Morfin. When he was fifteen, he went to see if Morfin was worth knowing, found a filthy, hairy wreck, and was told he looked like a Muggle down in the village that his mother had once run off with. At fifteen/sixteen, he killed his father and paternal grandparents, framed his uncle, and took his uncle's family ring as a trophy. He assumed, and was never told otherwise, that his father had only left his mother because he found out she was a witch - he did not know about the love potion.

He was obsessed with power at age eleven. That stayed throughout his life. He assumed, at age eleven, that dying made his mother weak and non-magical. He kept trophies of his victims, at age eleven. No matter where he was placed, he would likely have turned out evil, because he would have had classes with the Slytherins and been exposed to their ideologies.

Although, yes, he may have become a candy maker.