For business profits to rise, people need
    to to have disposable income

Imagine an island with two people on it and there is one tree that grows apples. And every other day, one of the two people climbs the tree and picks apples so they both have something to eat. Then the next day, the other person owes to climb on the tree because they are in debt to the first person.

Now, let's say one day, one of them discovers, hey, we can just give the tree a kick and the apples fall down on their own!

With the perspective you are proposing, the other one would have to say: Oh my God, don't do it! We will be out of work and starve!