If I understand correctly then this forces the shell companies to report their "secret" benefactors. So it keeps the small players from hiding behind a shell be

If I understand correctly then this forces the shell companies to report their "secret" benefactors. So it keeps the small players from hiding behind a shell because the cost of running a fake company with 20 full time employees would be prohibitive to them. The bigger ones can probably run a few of the exempt shells in parallel without loosing too much of their overall profit.