I am happy that you understood where I was going with this.
People whip up whatever they need it to be to make an argument. Sometimes we call it a currency because we can use it to buy things, other times its an investment. To reliably fit in either of those buckets is exclusive. To be a currency you need to be a store of value that is not fluctuation a lot, this means its a terrible investment vehicle.
For example, if you say that bitcoin has 7 tps and even with lightning will take decades to onboard everyone, it will become a store of value that you are supposed to buy and hold for long term. But if you point out how bitcoin has crazy volatility, it may become a currency that you don’t hold, just use to transact.