Not the way he said it. He meant literally sweep the forest floor, like sweeping up pine needles. He clearly wasn't talking about massive underbrush clearing.
Our problem is that decades ago the philosophy was to fight forest fires vigorously to contain them to the smallest possible area. In nature (and previous to modern fire-fighting techniques) fires burned until they ran out of natural fuel; underbrush. It's underbrush that causes fire spread, not the trees.
The 'contain and extinguish' allowed other areas of the forests to become thick with underbrush that in nature would have been burnt away during natural fire seasons. And very little money was spent on 'controlled burns' during the offseason to get rid of underbrush in a manageable way. Because 'contain and extinguish' meant it wasn't needed. Wrong. Nowadays, they realize that proper management of undergrowth is important and we see a lot more controlled burns, cutting of undergrowth, and thinning of trees happening.
Now when fires get started they spread rapidly through decades' worth of massive tinder-dry underbrush. Added in is the fact that the thick underbrush makes it hazardous and difficult for fire-fighters to even get into an area to create lines and backfires.
We humans have also been pretty rapidly encroaching on areas of the forests that a few decades ago were wilderness. Human habitation also creates fire danger. People don't create 'defensible space' or practice fire safety. Shoot, our neighbour (city 'transplant') didn't watch his burn pile and set fire to our back yard and it came within 5 feet of our back porch. It ended up burning almost 1/3 acre of our property.