I suspect that there are two main factors that make commercial foods seem cheap. One is the kind of fat used. At home, I make brownies, cookies and frosting with real butter. Commercial bakeries use much cheaper stuff.

The other is that commercial sources use mass-produced, premade sauces and gravies. They all taste the same.

I notice that the recipe linked above just calls for "gravy." It doesn't say to make the gravy. Apparently one opens a can or mix and ta da! The pies will reflect this poor quality ingredient.