After a few years of no tilling you can't compact your garden soil any more by walking on it than compacting your yard when you are walking across it. Tilling on the other hand really compacts your soil. Sure it looks all nice and fluffy right after you do it but wait until you have a hard rain.
As an experiment in a little area take a flat piece of land and till it and it will become a mud hole. That's my theory and I'm sticking to it.
