That argument doesn't make sense. Why would you treat miners different than holders of coin?
Because they are different.
Miners collectively get their 3600 BTC daily. Miners have running costs.
Holders get nothing. Holders have no running costs.
See, two differences.
This 3600, expressed in dollars, is proportional to the price of Bitcoin. So, at $1000 per BTC, this becomes $3.6 million. This is the maximum amount that the miners in total can spend on electricity. Miners will add new hardware until they get close to this limit, perhaps with-in 50%. This is a simple economic argument.
So, we are going toward a situation where miners have to pay perhaps $1.8 million daily, and utility companies are still not accepting Bitcoins. This means, this amount of daily money must come from
somewhere: miners sell on exchanges.
Also, once the price of Bitcoin changes, this amount changes as well, so we have a feedback mechanism, the higher the price, more miners have to sell, and selling tends to reduce the price.
Holders don't have this situation, and this is why we treat them differently.
