Putting a monetary value on something provides context- it's done in news articles of many types of natural disasters. Not many people (that I know at least) can visualize 400 hectares, or put into words a good description of the natural and ecological harm done by such a fire.

Saying that the fire cost 4m euros is at least something anyone can have context for, since even an urbanite who has never seen more than a handful of trees together knows what money is, and roughly how much some things cost.

Of course, most people will never have four million of anything remarkable, let alone moneys, but it's better than nothing.