Everyone who has a moral or legal financial obligation and does not have liquid cash necessary to fulfill that obligation needs life insurance.
If you believe that you are going to acquire, accept or inherit any responsibilities in the immediate future: i.e. you are getting married, expecting or planning a family addition, planning to buy a home, starting or increasing business debt, or in any other way originating or increasing moral/legal obligations, and you do not have the cash reserves to fully cover these expenses, you need life insurance.
One of the most overlooked needs is consideration of the non-working spouse. The replacement cost to hire someone to fulfill these daily responsibilities is easily thousands of dollars. Consider the salaries necessary to pay a cook, housekeeper, shopper, errand runner, maintenance person, waste disposal person, and sometime chauffeur. If you have children, add baby sitter, child care attendant, teacher, full time chauffeur and multiply cost of replacement ten fold.
If you have children, as mentioned above, and you are both a dual wage earning family, you both have a moral obligation to provide the necessary cash assets to cover the above and multiply those obligations by the number of children times the number of years between now and each child's age 18 to 21 being assured of enough money for food, clothes, shelter, and education. You both, most likely, need insurance.
Single individuals usually do not need life insurance unless they have monetary obligations, i.e. educational loans or auto loans, that exceeds their accumulated cash assets.