What the popular media gets away with is frequently an indicator of what creative people in general can get away with, at least in fictional terms. With the rising popularity of Dirty Harry, who later heralded in the more extreme vigilantes of the '80's, Marvel evidently felt that they could get away with a character like the Punisher - and lo and behold, they were right! (There are times I wish they WEREN'T right - I get awfully sick of the Punisher at times - but they were right nonetheless.)