HF made a working product (please try to keep up). The bankruptcy was due to an unfortunate confluence of adverse business conditions and early missteps like the first board rev.
Have you really never seen a tech company fail despite having a superior product? I believe you have, but are just being dishonest.
And those early missteps are not to blame to incompetence? They royally screwed up the first batches of boards, 1/4 of them arriving worked at the promised specs. It's only a superior product if it actually works for the customer, not on the drawing board
The superior GN1 chip has always been ready to push 700+ GH/s, given enough juice.
The incompetent subcontractor for the first board screwed up royally, and the next ones could only do 400+ GH/s until the Yoli and Habanero designs.
Converting that much clean power in such a small area is no small engineering challenge.