Right out of high school, I was trained as a meat cutter, working in a grocery chain in California. This was the type of meat cutting where sides of beef hung on hooks. We would then break the beef down into the various cuts of meat that make summer BBQ's so enjoyable. Meat cutters call it breaking, chef's call it fabricating. I learned an incredible amount during my time there and gained a deeper understanding of the farm to plate process. The training was the start of a life long interest/hobby in food processing, especially "From Scratch" techniques.
A lot of folks often say why not just buy it at the store, it's cheaper. As true as that may be, it's the learning process that's important. I'll try to cook/make/fabricate anything at least once, or a few times to perfect it. Often that will continue on, and in some cases, might be the end of that particular avenue of food exploration.
Below is an interesting video on how to make Hot Dogs. It might turn some people off, but it's nothing more than a very fine blended meat product. Most deli meats follow a similar type of process such as Braunschweiger and Bologna, just to name a few. A bit coarser grind and you have salami and bratwurst. Ever had a Gyro? That meat spinning on the spit is a blend of beef and lamb.
If you're concerned about the quality of ingredients used, you can always make it yourself and learn something in the process.