This may seem intelligent, but it's not necessarily true.  Even if people are mainly hoping to hoard, it would still be traded in a relatively liquid market, and there would be a fair number of exchanges between BTC and fiat currencies or between BTC and gold.

The main reason why BTC could not be used as a store of value in the long term isn't really to do with miners - it's mainly to do with utility.  Any cryptocurrency can have utility, so Bitcoin doesn't inherently preserve its value if it doesn't have utility.

BTC will generally function best as an alternative currency for certain niches.