Disclaimer for Dee, in my unprofessional opinion, those who end up in actual grave danger are very rare for the most par. IMO it's cautionary and rehab also prevents you from resorting to drinking should you have terrible anxiety in detox.
I've detoxed at home a couple times and it was miserable. I put myself in rehab last time and I'm grateful. Did I need it? No. But it made it much more tolerable, not to mention I got to speak to people that helped me in greater ways than just soothing the anxiety. The contacts and information I got there, when I had failed to find suitable help on my own, was far more valuable.