I'm not sure what current statistics are but about 10-15 years ago, institutional holders owned some 85% of U.S. company shares so the retail investor just wasn't catered to. As a result, very little is offered to shareholders as the administration costs just wasn't worth it.

ADRs (American Depositary Receipts) are instruments issued by a trustee (or some similar functionary) who issues the ADR to represent stock deposited with the trustee.