It seems most of his stories (i.e. Spiderman, Hulk, etc...) had a well-known, and widely-used moral at the end, but in The Punisher the message that comes across isn't necessarily a good one, because what I got from it is that 'Sometimes, revenge is the only option'.

So, was Stan Lee depressed or going through a hard time when he wrote the story, or he wanted to change it up?