An ERC20 token is a token that conforms to the ERC20 protocol, that's all that ERC20 means.
Associating the ERC-20 protocol with the current mania and nonsense of cryptocurrencies doesn't seem fair. It's simply a method of creating a sub-currency, which yes is often unnecessary but marketing is a powerful force so it happens.
Having seen small rural communities try and fail to create their own local currency years ago it's only a matter of time before some try again digitally.