Sorry for the derailment.

Without either a rise in the exchange rate or the sudden mass adoption of reasonable transaction fees or an increase in the volume of transactions (with fees), mining isn't a good investment. The spring/summer rush of preorders was based on a lack of awareness of how much hashrate had been bought by everyone else and hearing good news stories from the lucky early Avalon miners. Now the reality has hit home, I doubt KNC, Hashfast, Cointerra, Bitfury and the dreaded BFL are getting many new orders today. I guess the delay between the preorder date and the delivery date of most of these devices means the feedback loop informing people with spare cash that this a sensible investment was too long and thus, people have made irrational and unsound decisions.

Why aren't there more vendors? Perhaps the people with the correct skills and experience are getting paid more working for Intel, AMD, ARM, Samsung or Apple and don't feel that attracted to working in this kind of insane environment.

Philosophically, I don't really see any real advantage to the mining difficulty getting any higher. Back in the CPU days, more people mined and therefore the market was more accessible and the network more distributed and therefore safer. GPU and now ASIC mining reduces the pool size with no real advantage unless you have a larger share of the pie. I think this is where Litecoin has the better balance, but unfortunately it was derivative and second to the race.