For example - you define the problem as "the house is too cold".

To heck with the cause!

I'll put in a new furnace.

But the problem is - there is no insulation in the house.

So it is still too cold.

You have bought a new furnace and been cold for three more weeks. With no improvement in the problem. And now you must spend more money and time getting insulation put in the house.

Identification of the cause of a problem is crucial to solving it. The first time.