Can say the same thing about the superhero genre, which is the vast bulk of the American comics market, to the point the rest might as well not exist. Compare that to the manga market, where you have dime a dozen series about just regular people being normal. And as well as the vast bulk of slice of life stuff, if you just want to compare the cheesier harem manga and shoujo romance side of things, most of the protagonists in those are very wimpy etc and do not possess any amazing powers.
Sure there's wish fulfillment stuff about the weak kid gone good, but that's basically the entirely of the comics market in America (people gaining superpowers), whereas you have things like Love Hina, Ah My Goddess in Japan being pretty typical series. In those and most shoujo series, being average is the selling point and those series wouldn't work if the main character underwent some transformation to "awesome".
I think someone saying that "average person gets superpowers" is somehow indicative of
Japanese comic series vs American comic series is a bit hypocritical. Note: that Naruto is a battle shonen series. Of course such series are going to have the main character be an excellent fighter, the same as a sports manga will have the character be/become good at the sport in the manga. Because those are the central themes of battle shonens and sports mangas. That would only be a relevant observation about Japan in general if battle shonens and sports mangas were the bulk of mangas that are produced, but they are not.
Hell, Kimi ni Todoke was the best-selling manga in Japan this week. And you can't get more average than the protagonists of that series. Hell it's a shoujo series and the love interest dude isn't particularly rich or smart or athletic in any way, he's just a regular joe and his "claim to fame" is that he's not socially retarded like the heroine.
http://myanimelist.net/news/41180547And the 6th-highest selling manga was this:
http://myanimelist.net/manga/49341/"Aoishi Hanae is a 33-year-old woman who has a job, but no boyfriend. In fact, she's also still a virgin. It's not that she never had a chance to lose her virginity, but she let the chance pass by. At a drinking party with her colleagues, Hanae ends up confiding in Tanokura Yuto, a handsome young 21-year-old part timer at her company who also attends college, and who has recently broken up with his girlfriend. The next morning, she wakes up in a hotel next to him, and learns that they apparently agreed to start dating and then had sex that night. She has only hazy memories, and has no idea how to deal with the situation. Yuto is shocked that she doesn't remember, but hopes that they can still date. How will Hanae, who is older but much less experienced in romance, handle her surprising new relationship with the younger and more experienced Yuto?"
Comics about very average people's lives sell in Japan, and they sell really well.