Obviously, I don't have to agree with you 100% (except for the part that I should get out more).. but you're right on the money with that fact that the ASIC doesn't need to look "pretty". To get the job done is the right attitude and it's not like we'd look like poster boys ourselves either.
Furthermore, it left me thinking about the 1.25U competitor.. If they consume between 1.2 - 1.35kW power, why bother with such a small factor (and risk with not being able to dissipate the heat effectively, hence more noise for fans spinning at max)? Yes, it is the coolest looking kid on the blockchain, but as most Data Centers can normally only facilitate up to between 8 to 12 kW of power per rack (including the equivalent in cooling), where lies the benefit in 1.25U when you can only fit 10 of those into a 42U rack maximum, leaving 70% of the rack unpopulated from a density point of view? Data Centers that could facilitate more power are few and far between.
In this sense, BITMAIN seems to be spot on with the sizing - but it does come down to the price and how well they can position themselves on the market. No doubt more competition is coming and the big names of the past are looking to regain their position.
there are examples of server racks that are 3 antminers/4U = >30 antminers or 12kW. I assume with enough airflow the high power demand can be handled. Most racks though are not often equipped with more than 1 or 2 6" PDU units, generally capable of 4-6kW each depending on the outlet style. However, adding another PDU or simply employing multiple shorter but equally powerful PDUs would at least deliver power to the rack.
Its also quite possible not many datacenters expect such power density, and may not have enough available outlets per rack even if airflow/cooling are not a limitation
The 2 DC that I'm in are completely modular, I can order multiple 60A 3-phase connections if I wanted, so power density isn't an issue. I currently have 2 30A 208v single phase per rack, which is enought for 27 S1's overclocked, and the plan will be for 10 S2's. Depending on the DC and their rules, you may be able to go above the 80%, at mine, the only thing I lose is the uptime guarantee if I trip my own breaker.
2 of these gives you a 10KW rack
http://www.newegg.com/Product/Product.aspx?Item=N82E16812120346
That PDU doesn't take up very much space. If density required it, 4, 6 or even 8 is completely feasible, however if you're running a 40KW rack, you'll probably want to think about 3-phase.