If you don't understand killfiles then you've never been on the receiving
end of consistent insults and trolls. There are people who post in this NG
who basically ONLY insult others personally or insult their country. They
post aggressively whatever the topic may be. They alienate and annoy many
of us. These people don't respond to polite suggestions about their manner
of posting, and they often continue to post and post again in the same
topic threads until they finally generate a response. A killfile in this
sort of situation is like telling someone to stop bothering you. Like
finding an "off switch". Justified and necessary, unfortunately. There is
more than enough data to suggest psychological pathology and plain mean
spiritedness for a number of these persons.
To slightly correct you, a killfile is like filtering out static. Makes the
reading so much more pleasant