Why such "loose" permissions?

[Michael Hipp]

Why are users files, by default, created with such loose permissions?

Here's the typical perms automatically given to a new file created in my 
$HOME directory:

-rw-r--r--    1 michael  michael         2 Dec 11 09:12 testfile.txt

For reasons unknown (to me), often the perms end up being even worse: 
-rw-rw-r--

Is there some good reason to have the default permissions so loose?

This is a RH9 box, if it matters. I've noticed this behavior on every 
box I've loaded lately, even those configured as a "server". Is this a 
RH thing, or are others distros similar?

Thanks,
Michael