It never ceases to amaze me how people are willing to make blanket statements like this, while knowing absolutely nothing about the person asking the question.
For all the naysayers who are simply repeating "what you heard" somewhere, it is not possible to draw a single conclusion for everybody. My doctor was amazed after I did a high protein, high fat, low carb diet. My cholesterol level DROPPED to very healthy levels, I lost weight, I had increased energy - I could go on and on. I now enter into mild ketosis every time I feel like I am sliding health wise, and it always does the trick.
Ketogenic states are certainly not for everybody. I have known people that did very poorly on them, some who intially felt awful and then felt great, and others who experienced nothing. I've also known people who have lost a ton of weight, experienced many other beneficial side effects and very few if any bad ones (although constipation has been common).
Like I said, read up and then decide if it would make sense for you to try it. That is a smarter approach than listening to people who have almost religious beliefs about health, regardless of facts presented to them. The fact that you are asking at least shows you are open and willing to learn.
And the Genetic Genie just "passed you by."