Nintendo's massive financial woes are sadly a long time coming. I'm honestly going to miss Nintendo when they're gone, but they've done it to themselves. I might even shead a tear. I am also not an economist or a gaming industry expert, I just play one on the Internet.
(This is going to be long, so bear with me.)
Let's go back to the SNES. At the time, it was the most technologically advanced and sound platform with oodles of classic games. Chrono Trigger, fucking Earthbound dude. They were really riding high for a long time. Nintendo of course had their competition with Sega's Genesis, which also offered some solid titles. At least until they went to the Dark Side and tried to extend the life of the Genesis with the Sega CD and 32X. Sega tried releasing.... ugh FMV games on their awful platforms, while Nintendo kept going on strong. At least until they fucked up completely by not going to a CD format, which is what Sony did for the first Playstation. The Playstation sold like gangbusters and had the games to back it up. The N64 used a dated cartridge system and still had some killer games on the platform (Goldeneye, Conker's Bad Fur Day and of course Smash Brothers). Still, they lost the hardware fight while more and more developers jumped ship and defected to Sony's camp. Losing Square on Final Fantasy was bad enough, but it was only the beginning.
Then the Xbox came out. Most important about it was the fact you could FINALLY play games online like the PC Gaming Master Race (the people who spent exorbitant amounts of cash on gaming rigs) had been doing for years. The unwashed console masses could play online with their friends, which changed everything. Halo didn't sell zillions of copies for the single player campaign. The market and the consumer now expects good online play out of the goddamn box.
Then Nintendo makes the worst financial decision of their life. They create a entire gaming console based on a motion control gimmick and see bored housewives and eight-year olds as their ticket to riches. The Wii actually worked for a while financially. However, the problems of the system were glaring. The processing power was weak, the motion controls alienated 3rd party developers even more and the shitty excuse for on-line connectivity completely froze them out from online sales of downloadable content. You couldn't play the big blockbuster releases on the Wii. You couldn't play with your friends on a reliable network. You can't even play the cool little indie releases on the Wii. The housewives would bought the thing just for Wii Sports didn't buy anything else!
Nintendo is now basically the sole producer of quality games on their own system which is the kiss of death for a hardware maker. Rare completely became more and more of a punchline instead of Nintendo's vanguard (ok Rare WAS bought by Microsoft before sucking it up, thanks to whoever corrected me). Nintendo's own 1st party releases even got delayed numerous times! All the Wii's they sold started collecting dust in households, or sold for beer/weed money at greatly reduced value. When I can count the amount of good third party titles on LITERALLY one hand, you've got a SERIOUS problem. (Trauma Team, No More Heroes 1/2, Silent Hill: Shattered Memories. I didn't include Resident Evil 4 for personal taste)
The game manufactures in general lost the handheld market to Android and Apple, who are now making money hand over fist on cellphone gaming. I don't think the gaming companies are going to take that market back anytime soon.
People abandoned them in droves and Nintendo started to hemorrhage money until they can make a new console which looks even more bizarre than the last one, when the developers and the users have abandoned them in droves. But hey, another Mario Kart or Mario Party might keep the lights turned on in your office building for a while.
To quote Gordon Gekko, "You either do it right....or you get eliminated". Sorry Nintendo, but it's really been fun.