The tragedy of the commons relates to unregulated use of common resources.
I dont think this is any way relevant. Mining resources are not under common ownership and there is no common right to use these resources. They are generally owned by private entities trying to make a commercial profit and you have no right to make them mine your transaction. Miners can choose what transactions they mine so the use of this resource is regulated by the miners.
The common resource here is abstract. It is the willingness of users to pay tx fees. By accepting low-fee txs, a miner consumes this resource (that is, makes users less willing to pay tx fees) for his own benefit, at the expense of the total benefit of all miners. And, since Bitcoin needs miners, this is a problem for all Bitcoin users.
Nobody suggested that the mining devices themselves are a common good.
The demand curve for a product or service shows the relationship between the price of a product and the willingness and ability of consumers to pay.
In traditional economics willingness to pay for a product is not an abstract resource it is a variable in the demand calculation.
As I pointed out, if a certain percentage of miners offer lower fees (such as the charity miners) then this will mean that consumers will have the choice of how fast their transaction is likely to be processed. The fees charged by commercial miners will probably reflect the amount of discounted transaction mining available. Although all of this discounted mining will have to be paid for one way or another.
A miner consuming a willingness to pay resource for his own benefit makes no sense to me.
Suppose all the miners form a cartel. They will have no problem funding themselves; they can all agree not to include any tx that doesn't pay high fees. The users would pay this fee because they have no other choice.
Some users will try to pay a fee lower than the cartel's threshold. One miner decides to defect from the cartel; he includes in his block all these low-fee transactions. This costs him nothing, so this is a net profit for him (he benefits).
Seeing this, users will know that even if they don't pay the cartel's high fees, they can still get their tx included eventually. Thus, their willingness to pay high fees is lower (that is, the miner consumed their willingness). Thus, more users will try to pay low fees, and the total revenue of all miners decreases.
But it's not just the one miner. Every miner will, individually, have an incentive to include low-fee txs. This means that even with a low fee, it's easy to get a tx to the block. Thus, no user will want to pay high fees, and the total revenue of miners will be low (this is the tragedy - for the miners, and due to the effect on network health, for all Bitcoin users).
This is completely analogous to the classical instance of tragedy of the commons, where all herders would benefit if they all grazed just their fair share, but everyone is incentivized to defect and overgraze, depleting the resource and causing everyone to suffer.
I didnt quote blindly. I read it and thought it was relevant to the point I was making. The point I was making was regarding particular economic arguments that used the tragedy of the commons as their premise. I was not making any argument as to whether the equilibrium reached by free market economics would secure a network.
If we agree there is a problem (do we?), and we understand its moving parts, it doesn't really matter whether we call it "tragedy of the commons" or not. Though, I do believe that calling it that helps us gain insights from existing knowledge regarding tragedy of the commons problems.
We do not necessarily want to keep mining costs artificially high. What we actually want is to have a network that is secure against hash rate attacks. These are different things.
Sure, but unless we find a better way to keep the network secure, keeping mining costs artificially high is a subgoal.