Correct me if I'm wrong, but "doing nothing" means not participating in the allocation of productive force. The claim that it is harmful seems to imply that inflation provides the only incentive for economic activity.
Its harmful because it actually increases in value, not just because its idle. Someone has to produce the goods and services that are represented by this increase, and the benefactor is the one that just happens to have money.
The ones creating goods and services are trying to make those who save give up their savings. That's the game. If you can resist that, you deserve to get richer.
Think about it. lets say your currency appreciates by 10% per year and you can live a luxury life spending only 5% of your savings. Whats happening? You get richer every day by doing absolutely nothing. You could end up owning the world, but you say you deserve it? How? Wealth doesnt create itself, someone is making that happen and not getting the fruits of his labour. In the end everything will be owned by precious few and we wont have an economy anymore, just slavery.
I think the only proof we need to understand that this works is the fact that this is already the case.
No its not. You cant get richer today without taking risks and participating in the economy. Your money is worth less every year, if you dont do anything to maintain its value your fortune will dwindle rather than grow.