Feature of cash, not a bug. It's not the best choice for every situation, but neither is digital, which is why it's important that people have both options available.
Which is why the tinfoil me gets change before doing tinfoil purchases xD
Also consider Bitcoin as a "cashless society" alternative to the financial panopticon - no one's looking over your shoulder there and it's definitely not "cash".
I'm clearly in the 'it's nobody's business except for the parties involved' party...
'Cashless' as in 'cash is illegal' terrifies me. It's nothing more than a force multiplier for the power brokers (banks, govs, etc.).
There will always be corruption, theft, etc. But in one scenario, anyone can do it. In another, only the third (one) party can do it. Tell me which is better, oh starry-eyed Valley dreamer?