It's not a huge surprise that an artist from the period would fixate on youth in such a way. Picasso himself was obsessed with women far younger than he was. I mean, it's only been a manifestation of recent history that the age of consent for sexual acts was formalized at 16, or 18 depending on the jurisdiction. His work is definitely controversial given all of the social changes which occurred during his career, the wealth of consciousness raising which defined the 20th century. It remains, though, that the sensibilities behind his predilections weren't that far removed from the generations which preceded his, when young women had few opportunities to build a life and were forced to attach themselves to older men as a strategy for survival.