Bitcoins is like a product in the market we the consumers the users the holders are the one that can easily destroy bitcoins because their value is just high and expensive because of ourselves because we wanted to have it. The more people want to buy bitcoins the higher the value it will be so if we are not using bitcoins anymore the bitcoins will drops untill it will totally be destroyed because that is only that expensive because of a high demands which we are doing. So the life of bitcoins depends on ourselves if we do not used it anymore it will be totally worthless. Even government can ban it for the people cannot used it so it will became worthless again.