It's commonly used in a renovation situation: fertilize and water well in early August to get everything growing, then hit it with two applications of glyphosate spaced about 2 weeks apart to kill everything, then scalp it as low as you reasonably can and seed with quality seed of whatever variety/varieties of grass you want to grow.
If you believe glyphosate is relatively harmless (as compared to a series of 6-10 applications of selective herbicides to achieve not quite as good as the same end result), it's easy to understand why people are inclined to declare bankruptcy on their mess of a lawn and start fresh. Applying it in August, you could have a high-quality uniform lawn by October. (If it's far from harmless, then the series of selective treatments might be better.)
Rototilling to start over just surfaces a bunch of latent weed seeds that are in the top few inches of soil always. To start over, you want to kill everything growing without disturbing the soil and surfacing the weed seeds.
If you believe glyphosate is relatively harmless (as compared to a series of 6-10 applications of selective herbicides to achieve not quite as good as the same end result), it's easy to understand why people are inclined to declare bankruptcy on their mess of a lawn and start fresh. Applying it in August, you could have a high-quality uniform lawn by October. (If it's far from harmless, then the series of selective treatments might be better.)
Rototilling to start over just surfaces a bunch of latent weed seeds that are in the top few inches of soil always. To start over, you want to kill everything growing without disturbing the soil and surfacing the weed seeds.