ORIGINAL: TedMo
Why I don't know, but guess lazy, lucky? Been doing it that way for at least 50 years. Have had I guess almost every engine made from T D's to Saito 4 strokes and Sachs gassers. Suit yourself.
Luck is the best preventive for most any problem. A bit of castor in the fuel also helps for those of us who sometimes run short of luck with rust.
jess