In fact, it is a sign that the liver is overloaded, and that the body is rapidly trying to get rid said fructose.
Why is it a sign that the liver is overloaded, and how do you know? The body is using the energy it can use most efficiently as an energy source (thus carbs).
Increased skeletal muscle mitochondrial efficiency in rats with fructose-induced alteration in glucose tolerance
Generally, if the body can meet the demands metabolically to respond to a higher energy level, then we could expect higher mitochondrial biogenesis although these come with downsides such as increased oxidative stress. So it can meet the demands, but at a cost (is it worth it?). Most people are metabolically compromised in some way, so something like pure fructose or even glucose is usually not going to be good in large quantities. I believe you could have up to 8g of fructose every hour, more so if you are active and even more if you have more muscle mass or got done working out; in which case, you could probably spike it up to 75-150g depending on your body. Given they were fasted, most of the fructose was probably converted into lactate to energize the muscle mitochondria
Fructose metabolism in humans – what isotopic tracer studies tell us
I believe fructose consumption would be useful in high fat/protein diets although that's speculation.