If you look at the entire picture, you notice the gaming industry being a factor only in a short time period, since the 70′s. It took them around a decade until they made a name for themselves, and people started to know who companies like Nintendo were.
The times of the games where you ate mushrooms and stomped turtles are long gone now. They were great times for the game industry, as it exploded and became popular. It fast became a billion dollar industry, and Nintendo started to launch a lot of games each month. It might’ve been a fringe industry at some point, but it’s no longer that. At least not since Microsoft and Sony started making games as well.