Very true.
Business and personal should be held at opposite ends of the spectrum.
Thats the number one reason why I've never hired any friends, even though I've been asked 09439873295873405 times for a fuckin job over the last 10 years.
And if I ever hire someone, I'll be their at-work buddy to a point, and as much as I might want to, or they want me too, I won't become close friends with someone I've hired. Its a harsh reality, but its an important ingredient of a successful business.