That's the point. It's about the safety and possibly also some concern to the insurance policy.
From technical point of view, it does not mean you can't get an a.c. power close to 220V at home to run your 220V equipment although the single phase outlet gives you 120V. More accurate, you may get 208V between any two phases which is close enough to 220V.
V(LL) = square-root(3)*V(LN)
You may get 208V a.c. at home, either through selecting two output from different power outlet on the wall (typically from different location) or from any 3-phase outlet (for the stove in the kitchen or for the dryer in your laundry room).