We usually still end up needing to sift through 40-50 resumes and end up interviewing 4-6 people (over the phone or on-site)
Read this to my wife, who responded: "Thank you for wasting my time."
You may have hundreds or thousands of people who wasted a minute reading the ad. You have 40-50 (possibly out-of-work) people who wasted maybe 10 minutes and a buck or two sending you a resume, or an hour composing a cover letter. You have a half-dozen who spent hours, and maybe auto expenses, coming to and attending your interview, and experienced hours of stress responding to your people's questions. You wasted maybe a day of their time in the midst of a job hunt. All when you had a candidate you were happy with.
Did you EVER hire anybody except the one you'd started with? Or did you just get a warm fuzzy feeling from having found some possible alternates in case he drives into an overpass pillar during some night's commute?
But thank you for your honesty. Job hunters really need to understand the viewpoint from the other side of the desk. It will help them accept the repeated rejections that result from such "fair hiring" practices.