bitcoin is overrated and overpriced
For now though, yes it is, maybe Bitcoin should go under $100 and stabilize the price. But if it goes too low, the miners will become unprofitable and they will leave.
Miners will leave well before $100
The miners are not needed anyway, since most mining runs through only a few pools. The security the network is only supported by the security of the biggest pools. If the biggest pools, that make up at least 51% together, are compromised, then the integrity of the network is also compromised. And it doesn't matter how much hashrate is backing those pools.
Pure PoW mining is highly flawed. Miners are siphoning wealth out of the market, while contributing nothing significant.