We're killing millions of chickens in the US mostly so that other chickens don't get the flu. It kills a lot of them and it's making dairy cattle sick too. It's also worth noting that the Spanish flu in 1918 which probably came from pigs killed an estimated 50 million people so it's not like being concerned about an avian flu mutating so that it could infect people isn't a legitimate concern. So no. It's not a cold.

Sure, and those chickens exist because we like their meat and eggs. But there's also plenty of life that is simply inconsequential to us.

I think the problem is that from our human scale, mass-killings is the "best" method to eliminate the possibility of another organism causing harm for us. Hypothetically, if there was a more optimal (i.e less costly) method like just introducing some cheap catch-all combined vaccination/antiviral into their feed, we would just do that.

We don't have things like that, but that could easily be a consequence of man's limited research capacity, something that an ASI would not necessarily be throttled by. From an ASI's perspective, there might be many methods that are both less brutal and more optimal to fix the "humans creating a competitor" problem. Not that they would be aligned (Think halting human AI research by rewiring our brains to just not be interested in it [0]), but at least not deadly.

[0] https://www.youtube.com/watch?v=-JlxuQ7tPgQ