I won't dispute that there is a risk factor associated with transporting a loose propane bottle. However the hose is also a tripping hazard, especially a longer hose that is fully extended. Tripping around a burner or large hot pot is not a good thing.
. The tank maybe riskier to transport but it is safer to use because there is not a extended hose to trip over.
The hose eliminates the transportation risk but inevitably I seem to stumble on it at least once. Guess it's a matter of picking your poison.
I have a long hose and a extra tank and I can't decide which method is better.