In a democratic society, the majority might decide to appropriate money from the minority. If laws are applied uniformly, then how much money a person has in the bank is unimportant. If the government and its minions want to appropriate money from unpopular people or groups, then it wants to know who owns what so that it might make decisions to prosecute or confiscate property.
As banker Xavier Comtesse explained to Swiss Info in 2009, "The description 'banking secrecy' is actually incorrect-'protection of the private sphere by the bank' would be more appropriate." The Swiss, Comtesse continued, seek to "protect against any state despotism. This way of thinking has historical roots in Protestantism, which in Calvin's time sought to protect the people against the despotism of the powerful Catholic Church."
The author above notes a report in the Washington Post that 60,000 people have had property confiscated by the government under civil forfeiture laws since the year 2000 where that person was never indicted or served with a search warrant, let alone convicted of any criminal offense, but still were unable to reclaim their property. The issue is broader than "crimes" and "criminals", and when the government can aggressively confiscate property, reverse burdens of proof, etc., a wise person might well decide to invest in a country with greater protections against such abuse.