why do people help make old cars look bad

to take this discussion further, what comes to my mind everytime I buy one of our beloved old mopar projects, is coming behind someone else, and having to redo and fix "work" they did. like grade 3 hardware bolts that snap off? for example. the list can be long. generally I rather by an old car that has sat decades, and no one that lacks simple common sense and abilities has worked on it! ha
my last example only has a set of the "always present" 20 yr old air shocks with its little hole in the trunk. no big hill or deal for a "stepper"! ha