The rules of the sport were just different back then Tito, most fights in most states had to end by knockout or be declared a draw. Go on boxrec and look at some oldtime records and you'll see a lot of 'Newspaper Decisions', those were official draws but newspapermen had rendered verdicts but titles couldn't be won on a newspaper decision. So guys were much more apt to go for the KO even if others did have slick styles like some mentioned. Few guys though were sucessful as very pure boxers, some were though. Philadelphia Jack Obrien was but he had a whole sophisticated character outside the ring to bring interest to his fighting style. He touted himself as a refined gentleman type and boxed like one too.