Not every buyer will take 15 minutes on a property they intend to live in or own for a very long time. Some will take their time looking for red flags, oversights and other shortcomings.
During your house hunting quest, chances are you will only see a given house at its best; perfectly organised, expertly staged, and clean. This gives you a perfect picture that lures you into buying the house; however, you might be missing a lot; recurrent water problems, rat and termite infestations, past flooding cases, etc. These are the things that eventually cost you a lot.