Those millions also need to be well-versed with modern security protocols to keep their cryptosavings from being stolen, and accept the fact that not only the transactions are irreversible (which I guess is okay, considering that neither are Western Union's or Moneygram's), but sending to non-existing null addresses does not return an error, so any typo, a garbled message or a man-in-the-middle attack is also irreversible.