[lucianbr]

Once the AV vendors exist, killing them, especially by Microsoft, is clearly anticompetitive.

If you could prevail on a government to decide that, maybe it could work.

One thing I see, is that AV has a component of maintaining a DB of signatures of bad things. This does not seem at all the job of the core os. Would the Debian team maintain such a DB?

[bluGill]

It happens all the time that the big companies take something in house and kill a market. The car radio market is all but dead now that manufactures ship decent radios.

[lucianbr]

Bad things happen all the time. US school shoothings are a regular occurence.

[lotsoweiners]

Also Apple is notorious for killing software businesses by creating their own built in version.