Most candidates will not spend a whole weekend on any given application. How could they, when it sometimes takes hundreds of applications to get a job? Sometimes no compelling jobs are on the table, and other times they exceed the time you have available to interview.

As an interviewer/hiring manager, I think you should keep your examination light until you're serious about maybe hiring the person. It's less of a burden for everyone, including you. Most jobs aren't all that glamorous so stop expecting people to bend over backward to show stunning low levels of dignity and respect for their own time.