Probably not the best example... Did you notice the Net Profit line? Or the 15 year payoff? 
It's not ideal compared to what we are used to, but a 15 year payoff is 6.7% annually. This is considered to be a good investment in the non-bitcoin world. If you found such a good investment, you could ride it infinitely with a 4% Safe withdrawl rate.
Bitcoin people kind of have their heads up their asses when it comes to what a normal return is.
I think I might be one of those people with my head up my ass when it comes to normal return because I don't know what you are saying. How in the world is it a good thing that it takes 15 years to pay off a piece of technology before a profit is seen? Not to mention it's technology that can, within months, become inferior to subsequent ASICs or whatever new technology that will generate 100x the best ASICs being made now. These things could be obsolete in 6 months for all we know. If anyone thinks the bitcoin technology and circumstances are going to be stagnant for 15 years, they're kind of crazy.
I think at this point the honest person has to say to themselves with regard to ASICs, "I don't know". If you're a person of means in a good financial situation and can afford to throw around a few thousand dollars for fun, I say have at it and you are lucky, appreciate it and enjoy it. But if you live on a tighter budget like most of the world where a $1300 loss means something, it's probably in your best interest to be agnostic about ASICs and the bitcion ecosystem over the next 6 months and admit there isn't enough solid data to say anything with confidence...admit "I don't know".