>>283304005 (OP)
It's a common position for the MC to be thrust into something he knows nothing about with the need to preform. In a day he goes from being a nobody to being super cool/important. Most protagonist would grow into the role and become a selfless, heroic, benevolent protector. Shinji isn't that. He's different, and a lot of people say he's more realistic for that. It's also a reason why a lot of people call NGE a subversion/satire/critique/deconstruction. I'm not trying to gargle Eva's balls, just explaining why people like the ideas behind Shinji a lot. Shit, all this is just one aspect of his character.
Also in b4 someone says "because it's relatable to them because they're also losers."