Underestimated by what? He won the majority of his medals in weak competition, and it's not that impressive if we are talking not only about quantity but also quality. If women's canoe, which was much more hated than men's, had 500 meters race starting in 2010, the icon of women's canoe Laurence Vincente-Lapointe would easily beat grandfather Shtyl (Laurence at first only had 1 discipline, where she won 4 consecutive and 6 combined golds, than she added 4 golds in doubles and 1 in marathon, while Shtyl had more than five different disciplines). Again, if we're dividing the aggregate amount of gold by the number of events, where it was achieved, Shtyl wouldn't be number 1.