Unprofitable and Out of LuckSole proprietorships are the most common business structure in America, accounting for around 26 million businesses, according to the latest I.R.S. data. Many are sidelines — workers who pick up an occasional freelance project or collect royalties report it on their taxes as business income — but millions of people rely on their business income as their primary source of support.Yet, because of the S.B.A. edict that sole proprietors had to be profitable to get a P.P.P. loan, many didn’t qualify. Nicole Davis, an accountant in Georgia who specializes in small …