I've been reading this thread on and off for months.
It's interesting to see how things have evolved, and with hindsight we can see who was an Alpha shill:
https://bitcointalksearch.org/user/theym00s-215568 (active for 2 days, almost every post about Alpha and praising them - even a thread reminding people the pre-order was closing! haha)
It seems like most people here think it's black and white, either Alpha was scamming the entire time, or that they'll still deliver and it was 3rd parties who've caused the delays.
I think there's a broader range of possibilities, the most optimistic being that Alpha thought that maybe they could pull it off, but even if they didn't they would still get lots of cash because of pre-orders, or the other end being that it was a scam they orchestrated from the beginning (less likely).
Consider this, KnC miners is made up of a bunch of engineers, and their website links to their linkedins:
https://www.kncminer.com/pages/aboutusAlpha was made up of accountants, who would get other people to do the engineering.
This is important, because accountants know how to make sure they will make money even if they don't deliver. By saying that miners are business partners and making the pre-orders difficult to refund. I believe they had this plan from the beginning.
Getting in the cryptocurrency miner game is a bent accountants wet dream - greed from miners mean they'll happily send money for a pre-order, several months waiting for manufacture to be expected, etc.
So I think the most likely scenario is they hoped they could create a miner and make money as a legitimate business; this way they could make more money, using their reputation to sell new products in the future. If it was a scam the entire time they would have never bother investing in any chip production (although I'm not sure there's proof they have). But if things turned out how they have they'd still make a small fortune.