People are not required to think about the food, so they don't. For example, it's widely known that milk comes from cows, but not that the cow needs to be pregnant in order to do so, again and again. It's just not something that one faces in their day to day life. These things just spawn on supermarket shelves, and that's about it.
I wouldn't have thought we don't eat roosters. We eat bulls, so the line of thought that you use one sex for production and one for meat is kinda easy? (and hens for meat when they age out of laying etc)
It's actually somewhat the same in cattle. There are beef breeds of cattle for meat and dairy breeds for milk. Dairy breeds tend to be skinnier and don't grow as efficiently, so the bulls don't make good beef steers. There's kind of a specialty market in them for people who think a dairy steer raised and fed over a longer time for meat is better than the beef breeds that have been focused on efficient growth. But some dairy bull calves are just killed. The heifer calves are far more valuable.
TIL, very interesting. I guess you can't escape specialization anywhere.
If you have a chicken farm, you likely eat roosters time to time.