Because they figured out where the least risky money was to be made :\ On dupes who can't see where the difficulty is going.
Cointerra appears to be too late to the party. If KNC ships, they're largely screwed. High efficiency is a luxury only if the device can achieve positive ROI in the first place, efficiency then extends its life against electrical costs. I don't think a device shipping in Jan '14 with these stats can achieve positive ROI unless it's less than $2k, and then that's hardly any profit for the manufacturer so why are they bothering.
Late, late, for a very important date.
If KnC ships, HashFast customers are screwed.
If HashFast ships, then Cointerra customers are screwed.
The only way they can make a profit is by going for extremely high volume.
If they charge $1000 for 500Gh/s anyone interested in mining will basically have no choice but to buy. They sell 3,000 units, that's $3 million dollars, and 1.5Ph/s added to the network.
And if you think about it, there's probably no reason they can't charge prices like that. An Intel celeron chip is fab'd at 22nm and only cost $50, for example.
And not to mention non-28nm competitors flooding the market (Bitfury, Labcoin, BTCGarden, Active Mining, ASICMiner, Avalon, BFL, the guys from UK...)!