Personally, I have no issues with my guests looking through the data on my machines. Because if you are my guest and have that access to my house when I am not around then we have a transitive respect and trust.
To each his own then.............

I have my personal documents, budget and some financial data on my machine.....I dont want people to know that much about me......I strive for some illusion of privacy in my home....

Personally ...I dont want anyone to just happen to stumble over it....

Having no password is like leaving your house or car unlocked.....

IMHO....as always

MLF