While urine is ~95% water, and generally sterile for a little while, I agree that urine is bad to drink. Not only does it create the need to drink more water to offset the salt content, it does contain toxins, such as urea, which is less toxic than ammonia which is formed after it leaves the body; and these are forced to go through the kidneys a second time, only this time at more concentrated levels, which is bad in the long run. Also, urine is not always exactly sterile, as some diseases can be transmitted via urine, such as some forms of hepatitis, and also the bacteria from urinary and kidney infection.
Although, adding urine to a solar still can increase efficiency.
Urine can be reabsorbed within the body and recycled when the body becomes dehydrated. I think that if you have enough water in your body that you can urinate, you are not in immediate danger of dehydration, otherwise it would be recycled within and not expelled. Drinking urine as an emergency measure is ineffective and is nothing more than an absurd psychology. And those who drink it for health reasons are as equally misinformed.