This sort of behavior has been proved to be divisive for internet communities, and I advise against it:
The killfile behavior, is simply put: “sweep-under-the-rug”, “bury-head-in-sand” kind of behavior. Imagine that in a gathering where if everyone totally ignores other's voices except their own kind, then what cacophony would result? Similarly, if we ignore the problem of crime by simply using larger locks for our own doors, what consequence would result?
We are all human beings. Our surroundings are our organs and affects us dearly. In newsgroups, inevitably there will be certain individuals with foul breath at times. Killfile mechanism is a very good feature to battle such annoyances. This is not a reason for falling for the convenience of blocking your ears from dissenting voices or the nonconformists.