I think Mr Lynn overeggs the pudding somewhat but I think there is a kernel of truth in what he says - applied to American comics at least.
It does seem to me that most American comic books (and movies) are full of personal violence, clouded in a cloak of superhero fantasy - moreso today perhaps than even in the Golden Age. The concept of action is equated with crude violence.
There is little sense of personal development, allegory or irony as you might find in the Greek, Hindu or Nordic myths from which they were derived. American superhero mythology is a degraded mythos.
The contrast with European comic books is very stark. European comic books do have superheroes but the majority of publications are based on humour, action heroes (with no super powers), story-telling and characterisation.
I am, of course, stretching the point - setting myself up as an Aunt Sally to be knocked down in the interests of debate - but I do worry about the impact on young American minds of all that normalised violence. Is there a link with a nation so insecure, it's military is ten times larger than any other?