What's so bad about eating a cheeseburger?

Leviticus 11:13-19
(13) And these you should detest from among the fowls; they shall not be eaten, they are a detestable thing: the great vulture, and the bearded vulture, and the ospray; (14) and the kite, and the falcon after its kinds; (15) every raven after its kinds; (16) and the ostrich, and the night-hawk, and the sea-mew, and the hawk after its kinds; (17) and the little owl, and the cormorant, and the great owl; (18) and the horned owl, and the pelican, and the carrion-vulture; (19) and the stork, and the heron after its kinds, and the hoopoe, and the bat.

“Ideally, humankind should be sustained by the produce of the earth. When, instead, other living creatures are used as food, as is permitted, such use should be restricted to living creatures that sustain themselves with what grows on the earth and that do not prey on other living creatures or attack man... Humans are unable to live up to the vegetarian ideal set forth at creation; God compromises and allows humanity to eat meat. But Israel wishes to adhere to that ideal, even in compromised fashion, and therefore Israel consumes only those animals that themselves have not killed other animals.” ” (Baruch A. Levine, Leviticus )

There are four basic laws of kashrut:
1. Only certain animals may be eaten. There is nothing really special about the choice of which animals we eat and which we don't. God didn't make pigs and lobsters forbidden because they are more beloved than cows and salmon. Nor are they any cleaner or more holy. The idea is that we're not allowed to go out and just kill whatever we feel like killing. Our killing is limited to a specific list of permitted animals.
2. The animal must be killed in the most painless way possible. Even an animal designated for our food has feeling. You may kill to eat, but you may not allow the animal to suffer.
3. All the blood must be removed from the meat. Blood symbolizes life because blood is always moving in a living body and provides life to the organism. All life belongs to God.
4. All foods made from milk and all foods made from meat must be prepared, served, and eaten separately. Meat, which involves killing, symbolizes the taking of life. Milk, which nourishes newborns, symbolizes the giving of life. The two must never be confused in our lives.
In keeping milk and meat separate, we are taught that our real tasks are to limit our desire to destroy life, and to develop our abilities to give life. This is something our culture badly needs to learn....
What's wrong with a cheeseburger? First, we don't know how the animal was killed. Were those who killed the animal careful that the animal didn't suffer? Or did they just kill it the easiest way, even if it hurt the animal? Second, we don't know if they drained out the blood. Most animals we eat were raised on huge ranches and killed in huge factories where no one ever cares that they are living creatures. Finally, cheese which is made from milk, is mixed up with meat. Life is mixed up with death. Violence is mixed up with pleasure. Saying no to a cheeseburger is a way of saying no to a world that mixes up life and death, violence and fun.
-Rabbi Ed Feinstein, Tough Questions Jews Ask, pp. 58-60.