Consider that the miners will always produce a selling pressure on cryptocurrency (because equipment+electricity+labor costs), it stands to reason that cryptocurrencies will always have more sellers than buyers (again no new speculatary buyers for store of value, just pure currency as it was intended initially). This constant selling pressure will add inflation (increasing supply, decreasing price) to Bitcoin. Actually, once a stable price is reached for a long enough time, this constant inflation should make it a viable currency, and unsuitable as a store of value.