There are alternative scenarios out there to the fee pressure (funded by spam) that must increase in order to finance big miners. A gold holder is responsible for the safekeeping himself. Therefore it is in the interest of Bitcoin hodlers to run their mining in the future as well and take responsibility for safekeeping of the time chain. With Bitaxe, DATUM etc. the community is slowly shifting towards that. Big miners listed on the stock exchange sounds quite fiat to me. This may be just an intermediate thing that may disappear again.