I've played a lot of RPGs over the years. JRPGs, Western RPGs, and table top games. You name it, I've probably played it.
You may want to settle in as this is going to be long.
The "emo-ness" of heroes is attributable to the fact to two things: 1) most of them are teenagers or are just barely out of their teens 2) these games are marketed primarily to teens. When you were a teenager, you were on an emotional roller coaster. We ALL were. Anyone who says otherwise is a liar. A teenage hero on a huge emotional roller coaster is very easy to empathize with. When I was that age I empathized easily with Cloud in FF7 and Terra in FF6. On top of that, many of these protagonists experience some very real emotional trauma. As cliche as the actual event is, having your village burned and your parents murdered in front of you is going to affect you, especially at that age. One favorite "emo" whipping boy I've seen is FF10's Tidus. ((SPOILER ALERT))The guy was beginning to enjoy a good life as a star blitzball player, but he constantly found himself in the shadow of his father. His father,Jecht, was an abusive and narcissistic drunk. His sudden leaving made his mother die of heart break. Then, he gets dragged away from everything he's built for himself because his father suddenly needs him to clean up a mess he couldn't fix. ((SPOILER ALERT OVER)) I don't know about you, but I don't think I would be happy if all that happened to me. If you WOULD find yourself unaffected, than you can only be a robot.
Giant colorful hair and swords: These are just visceral aspects that appeal to teenage minds. It's the same thing as Ash's chainsaw arm, Wolverine's adamantium claws, or the Punisher's many implements of death.
Levels and character micromanagement: Every game in existence has a learning curve. RPGs tend to have higher ones. I wish more games at least gave people the option to fix their "mistakes" with minimum frustration. However, if a system is too arcane to you, you really only have 2 choices.
1) Rise to the occasion
2) Play a different game
Some people hate complexity and some love it. It's just a matter of preference.
As for levels, it was to help gauge a person's growth from a novice to a veteran adventurer. Some game stories (which cast you as a veteran) throw this dynamic off though.
It also helps players learn with simple options as they figure out the game. World blasting powers tend to be a bit much at the beginning for the wide eyed new player.
Role-playing: I agree up to a point. People want choices of who they want to be but there are as many choices as there are people. Even with the open worlds that Bethsaeda, Bioware, and Obsidian have created, there are still going to be limits. In Elder Scrolls, you have tons of customization options, but you can only be an "adventurer." You can't be a merchant. Trying to program every last thing, will result in the game collapsing under it's own weight as Yahtzee observed with Fable. Also, game machines can't read emotional responses. That's why you only have "goody two shoes or extravagant malevolence" as Yahtzee put it.
I can probably say more, but I don't want to overdo this.
Whew...Thank you.