Actually MS was behind the MSX platform which is the birthplace of Metal Gear Solid. The MSX did well in Japan and in parts of Europe, but for some reason failed in the USA.
Yeaaaah, kind of.
First of all, gaming was never seen as an "adult hobby" until the 7th gen, let's all be honest here. It was never seen as that during the 2nd gen- Atari - (don't even know where you took that from), and while Sony moved towards that direction, they only really accomplished that "adulthood approved seal" during the 7th gen, since before that it was very much as a kid/teen hobby (even if Nintendo had that reputation of the " for young kids" image, while Sony and MS had that "for teens and 20s "teens"" going for it.)
Second, Nintendo DID prove the industry authenticity and viability, not only bringing it back from the dead, but also getting record breaking sales numbers with it's consoles, games. Not to mention all the new experiences never before seen that it brought to the table, thus proving that it could be more than something to "pass the time"
Anyways, never got this recent trend of trying to downplay the vital role that Nintendo had in rescuying the industry from the blink of destruction.
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.