I like the other answer, but my personal fun theory is that Snape refused to use the most well-known hair potion (and the only example I can think of), which was created by....
Fleamont Potter, father of James and grandfather of Harry.
Henry’s son was called Fleamont Potter. Fleamont was so called because it was the dying wish of Henry’s mother that he perpetuate her maiden name, which would otherwise die out. He bore the burden remarkably well; indeed, he always attributed his dexterity at dueling to the number of times he had to fight people at Hogwarts after they had made fun of his name. It was Fleamont who took the family gold and quadrupled it, by creating magical Sleekeazy’s Hair Potion ( ‘two drops tames even the most bothersome barnet’ ). He sold the company at a vast profit when he retired, but no amount of riches could compensate him or his wife Euphemia for their childlessness. They had quite given up hope of a son or daughter when, to their shock and surprise, Euphemia found that she was pregnant and their beloved boy, James, was born.
