It's part of registering your product as a security in the US. If you look at other coins, they go out of their way to point out that they are not securities partly for this reason. For example, If you look at all of the disclaimers on the EOS distribution. The SEC supposedly does this to protect unsophisticated investors from themselves. It's a blunt instrument and does have the effect of only allowing rich people to get in on IPO's. It uses the assumption that any security can go to zero, so it keeps regular people from betting it all(or a likely unrecoverable portion) on a single security. Once a security is vetted to the point of making it on a regulated exchange(eg. NYSE, NASDAQ), it's fair game for anyone.