I do understand where you are comming from, but your example comes from a personal experience of a regional occurance, whereas this debate revolves around gaming as a whole, in the whole world.
Bolded: There were adults that were fans of gaming, for sure, but the perception of the general public was that games was for kids. And that's the whole point. Enthusiasts exist everywhere and have different ages, but these discussion, about impacts to the industry and overall perception, is regarded against the overall public and/or society.
So yes, not only did Nintendo save gaming, but it also made it more popular than it was.
More popular sure.
Looking at best sellers, Populous released '89 on Amiga sold about 4 million copies, Super mario world released '90 sold about 20 million copies.
Myst, best selling PC game until the sims, sold 6 million copies.
Kings Quest V only sold half a million copies and was actually also released on the NES (but censored for violence and religious themes)
Save gaming, nah. Make it more popular, yes they did. They made it more kid friendly as well.