It was just a lazy metric to measure effort and engagement, and that relieved the lecturer of the need to read the paper himself to see if you'd absorbed it and analysed its relevance correctly. I can't say I'm unsympathetic - the guy had 50 students to mark. I'm guessing this is standard in academia but if they'd said "read and include relevant papers" I'd have done a good job on half a dozen and the lecturer probably wouldn't have been overburdened either.