Well, the tragic reality is that both guns and cheese kill people and billions of animals.
Milk products causes cancer, diabetes and other diseases: http://www.adelicatebalance.com.au/
Milk causes innocent, feeling and sentient calves to be ripped away from their mother the first day they are born, and male-calves to be killed being only a few months old; and "dairy" cows to get killed when they are about 5 years old and can't produce "enough" milk to make the farmer happy. Cows can naturally become between 20 to 30 years old.
In USA people got outraged when Michael Vick enjoyed watching dogs fighting and killing each other. We rightly got enraged and claimed it was immoral because it caused unnecessary harm.
However the animal products that many people are eating are causing far more harm and death; and thus if we are consistent with what we morally believe in - i.e. that it is morally wrong to cause animals unnecessary harm and death - then we must also let our actions reflects what we have on our plates.
[See this article to read more about this moral principle: http://articles.philly.com/2009-08-14/news/24986151_1_atlanta-falcons-quarterback-vick-illegal-dog-dog-fights ]
I believe that people are very good at heart, but unfortunately most people's actions are causing a lot of harm and death.