Lustig is primarily concerned with fructose (and sucrose, which quickly metabolizes into a 50-50 mix of fructose and glucose).
Carbs in general (ones that metabolize mostly into glucose) have been widely available for a long time. They are also processed in a more "normal" way than fructose.
It might still be a good idea to reduce carbs, but I'm skeptical that the ketogenic diet is healthy.
Ketogenic diets are indeed not healthy over prolonged periods and should be limited in time. They're very effective though, so if you wanna do it just seek advice from a nutritionist and keep being supervised.
It's like putting the body in emergency mode, something you don't want to do for several weeks at a time.
Unfortunately, dieting will not change anything unless you really change your lifestyle and eating habits forever.
Any diet is a failure if it's just something you do for some time, just to get back to the old habits once you shaved off some pounds. Because of that, keto diets are not a good solution, since people get the wrong assumption about dieting ("I can eat like an animal and then do some keto to get fit again") and they're very likely to induce some sort of weight cycling (the so called yo-yo effect).
Therefore keto should be used with caution, by people who do that with knowledge and with the help of a professional.
Sticking to healthier eating habits over time is much more difficult and you need a very, very strong commitment. At some point in time, though, there's a switch that finally clicks and everything becomes more easy. Exercise should be a big part of this journey.
In the end it's much more rewarding and you'll discover a whole range of benefits. Weight loss will be just an insignificant detail, then.
For one thing: kidney stone are a very common issue when ketosis is sustained for a long period.
That means that you always have ketonic bodies in your blood (checkable with a quick urine self-test), which may not be the case for many diets that are just low-carb and not strictly "keto".
Why skeptical? It has been used for quite a while to treat children with epilepsy. If you're trying to lose weight, it makes sense to avoid things that are uniquely fattening (starches, sugars, etc). Ask anyone that was around before the low-fat fad of the 80's and 90's how you would lose weight - eat less bread, sugar, candy, cake, potatoes, etc.
Carbs in general (ones that metabolize mostly into glucose) have been widely available for a long time. They are also processed in a more "normal" way than fructose.
It might still be a good idea to reduce carbs, but I'm skeptical that the ketogenic diet is healthy.