Well, I don't disagree with the argument that major ASIC-mining players, in all likelihood, will be organizations, not individuals ( I do not necessarily agree that the mining organization and the ASIC manufacturer will be the same person, as such an argument would require one to make prediction regarding future state of a highly unstable market) .

However

a) I think that, even if some "hypothetical situation magic" were to make bitcoin strictly GPU-minable, matters would eventually evolve towards organizations and "mining moguls" hogging majority of raw hash power

b) all organizations and individuals doing mining would  flock into pools irrespective of whether we're talking corp-owned ASIC farms or GPU farms or little Joe's garage mining device.

As long as pools are in the picture, the argument regarding "mining decentralization" will remain rather hollow and pedantic, IMHO.