Anecdote:

I consulted for a large manufacturing firm building an application to track the logical design of a very complex product.

They modeled the parts as objects. No problem.

I was stunned to see the following pattern throughout the code base:

  Class of the object

  Instance #1 of the class

  Instances 2,,n of the class

I politely asked why this pattern existed. The answer was "it's always been that way."

I tracked down the Mechanical Engineer (PhD) who designed the logical parts model. He desk was, in fact, 100 feet away from mine.

I asked him what he intended, regarding the model. He responded "Blueprint, casting mold, and manufactured parts." - which I understood immediately, having studied engineering myself.

After telling him about the misunderstanding of his model by the software team, I asked him what he was going to do about it. He responded "Nothing."

I went back to the software team to explain the misunderstanding and the solution (i.e. blueprint => metaclass, casting mold => class, and manufactured parts => instances). The uniform response was "It is too late to change it now."

The result is a broken model that was wrong for more than a decade and may still be deployed. The cost of the associated technical debt is a function of 50+ team members having to delineate instance #1 from instances 2,,n for over a decade.

N.B. Most of the software team has a BS (or higher) in computer science.

P.S. Years later, I won't go anywhere near the manufactured product.