That is when they choose to spend a small portion of their money using cash. The rest is safely and securely linked to their person (or entity) in a legally binding and recognized way. Their "cash" may be stolen without trace, but the rest can't.

There's a big difference between paying for a coffee with cash, and carrying around the equivalent of a masternode in that wallet. It's not too big a deal if someone robs me of my walking around cash, but it can be quiet ruinous if my masternode is stolen and it's impossible to show where it went or who did it.