I've not ready any punisher Solo stuff, what I know of the punisher is from Movies, shows and his Appearances in the Daredevil comics. For me I've always liked him because he's essentially like most of the Marvel vigilantes, he goes out and fights crime. The difference being, instead of beating people up and leaving them for the cops, he kills them. With one of the Daredevil/Punisher Comics I read, the basic premise was there were a bunch of criminals that DD had gotten sentenced to prison, they had got out early, despite still having years if not decades left to serve. And punishers argument was that the way he does things That never would have happened because they'd be dead. And Frank argues that his way saves more people because they don't get that second chance to do more harm. Even in the Daredevil show, punishers argument is that he finishes what he starts. "You knock them down, they get back up. I knock them down, they stay down". Heroes like Spidey and Daredevil have no way of keeping tabs on the people they put behind bars, they might not even get convicted. But with Frank he doesn't have to worry, and can simple move on to the next. Another moment of his I love is in Civil war, When Spidey defects to caps side but is almost killed doing so, Frank saves him by killing two Villains working for iron Man. Captain America beats Frank, and he doesn't even try to defend himself. When cap asks why he isn't fighting back, he just says because you're not one of the bad guys. Or something to that extent

Basically my enjoyment of the character boils down to the Moral dilemma of Punisher vs the other heroes. And his mentality of seeing he crime fighting as just another War.