Quite a few people worship hashpower, even though the only thing that matters is the size of the potential malicious hashpower. As a user, you want the hashpower to not exceed 2X the largest malicious pool.
The miners have a funny game they play among themselves, where they constantly add more hashpower to steal income from each other. This does not translate into a betterment for users in any form: it adds no additional throughput to the system.
Hashpower that exceeds 2X the largest potential attacker is a giveaway to the power company. It increases the cost to mine, and reduces the viable zone for the coin. If the current and expected future price drops below the cost to mine, the coin will enter a death spiral.
Competing coins that use the same hash function require care, because they are potentially each other's malicious hash power. Though in practice, miners have been supremely docile to date.
When you don't know the potential size of the attacking pool, things might seem hard to foresee, and the natural tendency might be to say "we want as much hashpower as possible." This is not scientifically grounded.
When it comes to security, *all* that matters is how much malicious hashpower there is out there in the wild. If you're "ASIC-resistant," that includes all the CPUs and GPU farms out there. If it's an ASIC'ed hash, then all the specialized ASIC miners.
It's a pity that the dynamic set up in Nakamoto consensus encourages this never-ending race between the miners, beyond the optimal point.
We have seen some coins crash and disappear as a result of the price dropping below the viable zone. We've also seen them hard-fork to bring the difficulty back down. Both are protocol failures.
And of course, we've seen some people, usually the people who created the coin, spin up dedicated miners to prop it up even when it's outside the viable price zone. Such coins are de facto centralized and offer little value beyond a database.
