You are raising some really great points.
I think part of why we look at this differently is the difference in living in Missoula verses living in New York. I agree that if you have a good, established soil culture or if your native soil is a rich loam, you will not need to aerate regularly. On the other hand in many areas aerating can really help establish a good soil culture. I live in New York where the native soil is mostly clay-like.
Most turf grass here is a combination of Kentucky Blue grass, Rye, and Fescue-so both bunch grass and rhizomatous, all cold season and none of them native. Some people will add warm weather grasses like Bermudagrass to outcompete the weeds when the cold weather turf is dormant, but many people don’t love the way it looks and it can be aggressive.
Over a decade ago I spoke with the soil scientists at Cornell’s Soil Center in Amenia New York, and they suggested aerating and leaving the grass longer. This helped tremendously. So did adjusting the pH with lyme in some areas.
Aerating helps the roots grow because they aren’t compressed (think a seed starting mix that is loose and loamy), and supplies them with oxygen. It also lets water and nutrients get to the roots more easily. The plants nourish the soil bacteria, building up a good soil culture and a large, productive layer of topsoil. When the blades of grass are longer the roots are longer, there is more photosynthesis and the roots weep carbohydrate that feed the soil bacteria. So longer grass and aeration helps build up the soil. The cores from aeration stay on the lawn, but start adding a looser, loamier layer, especially with clippings, fine leaf mulch, and occasional compost if necessary. If you have great soil, I agree you don’t need to aerate. I also think it is easier to get good soil in a meadow with a variety of grasses and legumes that you let grow most of the season.
Overseeding is suggested by both Cornell and Rutgers organic programs to outcompete weed seeds on mowed turf. An established pasture does not need it. But here we suffer from both Japanese stilt grass and crab grass in turf. The seed is ubiquitous, and overseeding at the right time helps out-compete these weeds. They are both annuals, and mowing before they go to seed is crucial in controlling them.The alternative is just tolerating the stilt grass for a month or so in August.
Then there is the earthworm issue. I’m mentioning this only because I think you might find it interesting, not because I think it is practical, and it only pertains tot he Northeast. I just don’t worry about it, but many ecologists in the northeast consider earthworms an invasive species... Dr. Peter Groffman is a microbial biologist and researcher at the Cary Institute of Ecosystem Studies in Millbrook, New York. He says glaciers killed all of the earthworms in the north east during the ice age, and the temporal forests of the northeast developed without them. Forests south of New Jersey developed with them. Why are earthworms bad for temporal forests? He says the forest soil of a northern temporal forest is characterized by a thick forest floor, or duff layer that is 5 or 10 centimeters thick and you can pick it up like a carpet. It is consists of decomposing organic matter and leaves. This duff layer is important in carbon sequestration and water retention, two crucial functions of the forest. Once earthworms are added to the forest, in two to four years the forest floor disappears. This not only leads to diminished ability to retain carbon and buffer floods, but also facilitates the invasion of nonnative plants and invasive species. There is also a loss of spring ephemeral plants and understory growth. The trees then have an increased sensitivity to drought and climate changes with these changes in the forest floor. Soil fauna such as salamanders suffer, but white-footed mice that transmit Lyme disease flourish, leading to an increased tick population. He is studying this in Cornell’s Arnot Forest and Millbrook’s Tompkins Farm. He said that the worms that we see in rich soil don’t make the soil rich, but instead enjoy rich soil. This is different from composting where the worms are clearly wonderful! Anyway, this is just out of interest and I hope not took wonkish!