Why? No practical reason really. It doesnt add flavor or change cook times etc. Its just there for appearance. For me smoking (cooking in general) is a hobby. Anything I can do to change it up a bit or to experiment adds to the enjoyment. Im a tinkerer and will rarely leave well enough alone. This smoke ring debate has been discussed many many times. It all comes down to personal preference. I dont bother most times but even when I do, the results are mixed with an electric smoker.