Well, for one, Debian and Debian-based distros make your home directory readable by everyone by default.

Security is riddled by traps. If you can afford best possible level of isolation, why not do it?

Yep, I broke locate when I made my home 700. Its user could not traverse my files anymore. I had to make it run as root. A better design would be to traverse each user home with that user id but apparently it assumes that the home dirs are 755.