Bitcoin people kind of have their heads up their asses when it comes to what a normal return is.
Let's use your post as an example: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.