I'm not sure why that's depressing. You've managed to filter out the majority of people you'd not want to hire with just a simple set of tests.

Perhaps a way to screen out many of these people without spending the time administering the screen is to have a simple coding test that these people complete before you'll even have them in for an interview. A couple places I've interviewed with did this, and they both expressed high satisfaction with the reduction in interviews of hopeless candidates that resulted.