I did not mean to imply that I LITERALLY just collected business cards and spoke to no one. Of course, doing so at recruiting events would be absurd.
So, I don't think it's a common misunderstanding. I think it's common sense that you're supposed to speak to the recruiters and build your network.
The recruiters aren’t there to let you know they’ve got jobs. They’re there to talk in person to young people, and figure out which ones have passion for the company/project/etc., and put the passionate people’s resumes at the top of the queue.
If you just pick up a business card, it’s indistinguishable from being a cold call/spray and pray resume sender; companies and recruiters get so many of these there’s a good chance no human ever even looked at your resume.