I'd say the term "store of value" has meaning in the context our current world of fiat money, where you need a hedge against inflation. In the case of Bitcoin while it is still not yet mainstream I think a special definition is useful: an asset that retains or grows its purchasing power over the years (particularly in contrast with fiat money), with growth of course being considered even better as a store of value than simply staying level. Also the difficulty in confiscating it should be part of its store-of-value merits.
There is certainly a difference between forms of money that work well, and forms of money that don't, that many people have observed throughout history.
The problem is that the explanations for those observations are not correct, because they are tautological. They show up in conversations with goldbugs all the time.
Q: What is a store of value?
A: Anything that has the properties of gold.
Q: Why is gold a store of value?
A: Because it has intrinsic value.
Q: What is value?
A: It's what anything with the properties of gold has.
Q: Can you give reason why I should buy your gold other than that you want to sell it?
A: ...no.