Because sending $2000 to everyone cuts out the bureaucracy, which always ends up ensuring that the specially targeted handouts go to the wealthy, well-connected, and ethics-challenged crowd. People who own a hundred separately incorporated "small businesses", and have lawyers and tax accountants who make sure they always qualify for every government hand-out. Give the $2000 to everyone, and nearly all of it gets pumped right back into the economy immediately, with a lot going to actual small businesses in the form of purchases of goods and services.