Why is 127.0.0.1 used for hosts file redirects instead of 127.0.0.0?

You can obtain pre-compiled hosts files used to block ad sources, phish
sites, malicious sites, or other content (based on an IP name that has
to include the hostname in the URL since this is, after all, a *hosts*
file). One such pre-compiled hosts file is the one from the MVPs site
(http://www.mvps.org/winhelp2002/hosts.htm). However, I'm wondering why
the loopback address of 127.0.0.1 (for localhost) was chosen.

127.0.0.1 actually exists since it is the loopback interface defined in
your NIC. If you put http://127.0.0.1/ into your web browser, you see
it cogitate a couple seconds before erroring. 127.0.0.0 is the default
network. Putting http://127.0.0.0/ results in an immediate failure.
The web server won't try to connect to a particular host.

The idea of using 127.0.0.1 only works if you are NOT running your own
web server. If you are then obviously the hosts file that redirects to
127.0.0.1 is trying to connect to your own web server when the intent
was to block a connection to the content at the specified host in the
URL. This means you could see content from your own web site
intermingled with the web page (where you were attempting to block some
content or that site using the hosts file). Well, obviously it will
take some time to retrieve web pages from your own server. Any local
process listening on port 80 would connect to the 127.0.0.1 address you
use in the hosts file for redirection (in trying to block content).

So why even bother trying to use the loopback IP address? What happens
if you have a web server that is local and listening on port 80 (for the
HTTP connects)? Why waste time trying to connect to your local web
server, if you have one or to even try to connect to one, if the point
is to block content? Why not use 127.0.0.0 which results in an instant
failure and would never connect to your web server should you ever
decide to run one? Or use 127.0.0.254 which is unlikely ever to get
used in your internal network path to define a host (but even that takes
longer to generate an error than using 127.0.0.0)?

Why the focus on using 127.0.0.1 to block content using the hosts file?
Why would you want your web browser to even try to find localhost when
the point is to always fail in order to block that content?