It could just be because of Shinji's character depending on your perspective he could be a whiny little bitch(he kinda is). But it could also just be because people just like different flavors of depressed people some like angry depressed people while hating mopey depressed people.
Alternately, Shinji's depression is completely irrelevant and she sees him as a selfish user who doesn't care about anyone outside of how they can make him feel better.
I do kind of interpret him that way too but I don't hate him for it(even if it's kind of annoying sometimes) I actually kind of like that he's selfish. On another note I hate when people excuse the things he does because of his depression or his age.
