You are factually correct, but the intentions are a bit murkier. The explosion of video arcades in the 70s and 80s was due to how lucrative the machines were as an investment, not due to any passion on the part of the owners. The value proposition for arcades at the time was basically like gambling, but not illegal. While arcade games have always been skill-based, that's not the same as "fair," at least in the modern game design sense.
Yes, with repetition, you can eventually learn to beat Ghosts and Goblins on a single quarter, but the game is not going to just let you do that on the first try. Games of that era are designed to lure you in, then kill you with something completely out of nowhere after your 3 minutes are up and it's time for the next person in line to put in their money. This self-reinforced when you saw someone who had put in the reps getting really far on one credit, so you would think you can do that. But no, you can't. You die at the end of the first stage like everyone else.
It's not gambling, but it's still designed to extract money as efficiently as possible.