There are a couple reasons we do this, the main one is convenience in the galley, the other is availability of quality meat. There is quantity meat in the islands, but it can be hard to find, especially when you are buying for 8 people.

I cook bacon and sausage at home. Makes breakfast so much easier, just warm up the meat and make pancakes, or eggs. Also good for BLT's (no messing with all the grease)

I make homemade spaghetti sauce, just boil noodles and you have a nice dinner.

I marinate a pork tenderloin, bacon wrap filet mignons, per-make hamburger patties and season. Everything is done, ready to throw on the grill.

I also make taco meat, again, no messing with grease, just heat up, add some cheese, lettuce and tomatoes, dinner is done.