you cant be completely right on both points. if mining manufacturers are missing promised delivery dates then difficulty shouldn't be skyrocketing... so someone somewhere is delivering their mining asics!
Right now, pre-orders are just gambling because mining manufacturers constantly miss promised delivery dates and difficulty is skyrocketing.
Yes I can be right on both counts. Most mining manufacturers simply deliver late, making it impossible to calculate ROI with any degree of accuracy.
The larger problem is taking pre-orders for a product that will deliver (hashing) for (price,wattage) when what really matters is difficulty. A .5TH unit may be the equivalent of a BFL Single by the end of the year if everyone who says they will deliver manages to deliver, plus the 'unknown' factor adds even more doubt.
No more "pre-orders", either have a product or don't. If you come out of left field and can deliver next week you will clean up and can retire.