unfortunately I have to agree:

network topology and brittleness aside, the optimum engineering solution, the solution that gives the highest hash per $ is one specialised datacenter, close to a power generation facility. of course it could not rest on its laurels for long as competition would evolve to undercut it.

i think in the future their will be a smaller number of competing large hashing operations. very large data centers.

but there is more to worry about than the trend toward centralisation... a fractional reserve like protocol will be created atop the base Bitcoin protocol where user debt becomes bank credit all over again.

still you will make good profit by holding. HODL!