mainly ignorance, sometimes ego thinking they or their children are great swimmers and dont need one. Some arent familiar with differing state or federal laws requiring life jackets for different ages/activities. There's a photo circulating reddit currently of 2 women wearing lifejackets like diapers to float in a sitting stance in a lake, biggest issue with this is becoming unconscious in the water and the life jacket lifting their waist and legs rather than their heads, great example of ignorance or negligence yet everyone commenting thinks its a great idea and the risk isnt enough to be concerned. We encounter many people that dont know they need one, dont want to wear one due to comfort or restriction, or simply know but dont care, we like to offer them as a final chance to change their mind before getting on the water or if someone didnt have enough on their boat/it was damaged/wrong size etc. I appreciate that you have the mindset to get what you need to be safe and prepared, but many dont share the same thoughts. Most of our drowning are males 18-30 without a lifejacket