The question we're addressing here is if there is economic harm in bootlegging object code for a system that is no longer manufactured. Arcade hardware applies just as much as console hardware, even moreso since the arcade machines were produced in quantities much lower than the catridges for popular home consoles. The response being mentioned in the grandfather comment was if owning a copy of the original object code on chips satisfies the copyright concerns. If you own the original game, then you should be able to sleep soundly at night that you're not stealing from the author of the game.

Namco (& Midway in the USA) stopped making these arcade machines 30 years ago. One could easily argue that that is WAY out of production and there's no possible way Namco could be harmed by bootlegging Pac-Man ROMs into a MAME cabinet and placing it into a Chuck-E-Cheese.

But, lo and behold!, Namco is making arcade equipment and selling it again. There's definitely an economic impact now.