Quoted from d0n:alternatively, pinball companies could produce more games! They don't because demand & prices would fall. Just like Harley-Davidson motorcycles, they let the motorcycles trickle out of the factory to keep the demand and the prices artificially high.
I think you mean to site either the DeBeers diamond cartel or Girl Scout cookies. They both inflate their value by creating artificial scarcity through tightly controlling their market availability. Harley wishes they could move more units. Their value is tied to the aesthetic of the Harley lifestyle and that it is an American brand, not the rarity of them (and certainly not the quality or engineering). Supply chain shortages are hitting them like every other large manufacturer.
Pinball is still the industry that nearly collapsed in the last 25 years and it only limped along though cost cutting measures to make it through to today. I don't think any manufacturer in the business today wants to go through a wild, ill thought out expansion of their production facilities when the demand for individual titles is so variable.