Yes, the study authors do cite unaccepting parents as the number one cause, but present a narrative different from the classic "comes out, gets thrown out" trope. They say evidence leads them to believe that fraying relationships over time lead more often to homelessness than a single, dramatic moment. And often, youths leave home semi-voluntarily rather being tossed out by force. They don't feel they have much choice, but it can unfortunately make it harder for them to access resources they need.