I would have to agree about amending soil to a point where tilling with a roto tiller is no longer needed. I have raised beds and some ground level beds going into their third season.
Each time, it gets easier to work the soil for planting. I use a garden spade to loosen, a couple minutes with the hoe, and I'm ready to plant seeds.
I'll watch neighbors with their tillers spend hours going back and forth, back and forth. Some extend the tilling over a few days in order to loosen up all that compacted clay, which is prevelant in the Piedmont region of North Carolina.
They don't amend. Next season, it's repeat the process.