Well, I don't necessarily agree with powerplayers, but I can see where they come from. With all of these action movies and animes portraying characters (especially main ones) as being larger that life, it's normal for younger audiences to be influenced by these portrayals, especially if they haven't seen anything else.
What movies are the most exiting? The ones where the hero gets almost killed and then rises right back up and the cycle repeats. But for that, you need someone who can make it look exiting, if I was batman... the entire franchise would quickly get duller than a rock. Look at batman running away from the bad guys, look at him trip and fall on even ground, watch as he stumbles and gets ridiculed.
No one wants to be that guy, people want heroic characters, strong, flawless heroes to be idolized and respected. Of course someone who's never been in any lethal danger will not actually be able to handle a life and death situation mostly because of fear and in the eyes of many people, that's a flaw, so there's one less motivation to make a regular character.
People don't realize that fear may be a good thing, a quality that lets you decide when too much is too much. So they make fearless characters, powerful destructive machines because that's how they're shown on TV.
Of course there are epic characters that aren't perfect and have flaws, but most people only see the positives and do not pay attention to the flaws, so then they do the same with their characters.