The main reason many middle class families want life insurance is the need to provide a substantial lump sum to replace lost income if a parent or breadwinner dies.
Young families are often carrying large mortgages and are meeting the expenses of growing children. This is why it's important for them to choose a life insurance product that provides the desired death benefits at a much lower current cost, which is term life.
By the time many adults reach their fifties, their children are usually grown, their mortgage will typically be substantially paid down so they now have a good deal of home equity, and they will have accumulated other retirement savings. As such, the need for a substantial death benefit from a life insurance policy is much less important in later life.
So for many young couples, it makes sense to focus the bulk of their life insurance on term life which is more cost-effective at that time of their life when life insurance is the most important.
If you are younger, you may find it confusing when an insurance agent recommends whole life policies when an emphasis on term life would seem the better choice. Be aware that insurance agents typically get much higher commissions for selling whole life products and those commissions often can have an unfortunate influence on advice provided.