Like i said, because you have been told to and you accept with unquestioning obedience (by the way, this isn't a compliment).
Not eating pork and many other things is couched in religious-speak, but the real reason is that health-wise eating anything not near the bottom of the food chain has bad effects in the body. Why? ONE of MANY reasons is that every animal ingests poisons of some sort. The next animal up the food chain concentrates those accumulated poisons. The further up the food chain, the more concentrated those poisons become. In other words it is not safe to eat animals that are SCAVENGERS. Making it a "sin" to eat those animals causes many people to avoid such meats. Pigs will eat almost ANYTHING, even their own PISS and SHIT. They are one of nature's vacuum cleaners helping to keep the Earth clean. Basically they are one of nature's SEWAGE PLANTS. Would you go to a sewage plant and eat the sewage there? If not, why would you want to dine on one of nature's sewage plants? The pig is so poisonous that it has poison ducts near its hooves to DRAIN POISONS from its body. There are many other animals that are part of nature's vacuum cleaner systems, and NONE of them are safe to eat. For example, water dwelling animals that are BOTTOM feeders help keep the waters of Earth clean. Some examples are oysters, clams, catfish, etc. Not only are they not safe to eat, but anything that feeds on them is also not safe to eat because of accumulated poisons that work their way up the food chain. When you consider flying creatures, there are a host of birds not fit to eat. Like eagles, crows, sea gulls, etc which are all part of the natural vacuum cleaning system, helping to keep the Earth clean, all scavengers. Basically, SCAVENGERS (AKA natural SEWAGE PLANTS) are NOT safe to eat. I have no idea why camels, elephants, rabbits, and so on are banned as "sin," but based on what we do know, I am sure there is a good reason that has not been discovered yet.
Pork/Ham can be made safe to eat. This has nothing to do with why Islam forbade it. Those who bring all of those reasons are just apologetics who try to force reason on religion, which never works. Islam forbade eating pigs, animals killed by other animals, animals who die from a high fall and animals sacrificed to other than God - They all are at the same level of sin. You can try to justify it as much as you want, but it will not work. Don't try to find reasons why religions do/say things, religion != reason != science regardless of what anyone says.
I am a Jew and currently in a nation forbidding pork. I miss eating pork products. Back when the Torahic scriptures were manufactured, there were certain diseases only pigs carried. Now it should be noticed that this is just another way to restrict people from following their appetites. You live once, people. Free your mind before deciding on what and what not to eat!