Okay, an immigrant setting up a convenience store may not be as flashy as an Elon Musk coming over here to found Teslas, but they still bring benefit to the receiving country. Even if they only employ relatives, they still benefit the economy, whether they buy from suppliers or spend their hard-earned money in the economy.
Actually, the little economic activity generated by such people alone is not in the national interest, and it is insulting to compare them with genuine investment immigrants, although the investment immigration program is also deeply flawed. The government recognizes this, and the immigrants who buy convenience stores or gas stations and employ their immigrant family members typically immigrate to the US on family-sponsored or diversity lottery visas. In order to qualify for investment immigrant status, you must create at least 10 jobs for Americans, which doesn't happen with these types of businesses.
Judging by the McAuliffe-Rodham EB-5 scam, you dont even get 10 jobs with the actual investor visas.