The longer we live, the better our scientists & doctors will become at improving our life-expectancies. Australia now has one of the highest life expectancies in the world (higher even than USA and UK).
As a result we can expect to live longer but we must also expect to require increasing amounts of assistance in our later years.
In short we are likely to rely upon an increasing amount of care towards the end of our lives, and this care will be provided by people who will be in a position to influence us regarding testamentary gifts.
The role of carer can be quite an intimate one. Confidences can be shared; friendships are established. It becomes a “trust” relationship. However the potential inequality in the relationship (the reliance that is necessarily placed upon the stronger person by the weaker person in the relationship) creates a ready climate for exploitation.
As a society, we judge the respective “bargaining” positions of many common relationships, such as employer/employee or teacher/student. Where one party is thought to be too weak to properly protect their own interests, the Government & the Courts will intervene to offer protection against unfair or unreasonable behaviour.