Because some employers discriminate, it's really disgraceful that employers are even allowed to request such information, this country has terrible discrimination laws.
There is also a really tragic side to this.
People with alcoholism sometimes don't go to the Doctors because it will go on their medical records and may be seen by an employer.
End result, they die from drinking because they wouldn't seek help
Don't try and pick holes in that, it's a fact.
Also any life insurance becomes null, so if you are the partner of a drinker then you are on your own financially when they die.
To what extent people with depression avoid seeking help I don't know, but I bet some people don't want such a thing being seen by employers.
The whole thing stinks, you can't now discriminate on sex with regards to car insurance, so medical illness like depression shouldn't come into life insurance. For one thing it's personal, I wouldn't want some pencil pusher having access to all my details, or for some gobby cow in HR to know my history.