"Could've, should've, would've. Don't let it bug you, man. You're talking to me now, and that's what matters. And whether you're ready to accept it or not, you can't change what happened." Accepting their parents' deaths had been difficult, too, but Elliot had had no choice but to accept that. He didn't have spectral visions of his mother and father to tell him to move on, either.
David's shouting didn't surprise him. He shoved his hands into the pockets of his hoodie, waiting for his brother to get this burst of emotion out of his system. "Oh, really? Would you have traded Mr. Hamish? What about Slo Jam? Or that guy with the two young daughters he has to take care of? Or Rae? Would you have traded any of them for me?" Elliot knew this was hard for his brother to accept, but it wasn't like him to be so heartless. To wish for the deaths of other people, just so he could keep his older brother around. Granted, Elliot probably would've felt the same way.
His expression softened when David said he wasn't sure he could be alone forever. "But you're not alone. Don't you see? There are plenty of people still alive who care about you. Rae, for one. Allie. What about Allie? She cares about you. She wouldn't let you be alone."
"A lot of people don't deserve an early death, David. Not just me. Sad people aren't the only ones who can die." Elliot was fully prepared to stick around and make sure his brother never felt like he was alone, never felt like he didn't have anyone. Elliot didn't want to move on. Not if it meant he had to leave David in this state.
He perked up when David told him he could get the message to Rae himself. "You actually know how to do that?" Stupid question to ask his ghost enthusiast brother. "You think it'll work?" He had to speak to Rae, at least once more. To ease her grief, help her move on. And, if need be, he'd stick around for her, too. Rae and David wouldn't have to be completely without him.