I think Nintendo's problem is a simple one but has a very difficult solution.

I'll start by saying I don't believe the industry is big enough for 3 similar consoles. Last gen saw a near 50-50 split of the core gamer crowd between the PS3 and 360. Nintendo went a completely different route and cornered the casual crowd.

This gen, the core gamers are leaning more towards the PS4 which is very similar to the XB1 but "better". And the PS4 pulling away from the XB1 shows how much this industry doesn't need multiple similar consoles. Nintendo tried to catch lightning in a bottle again, they failed.

So they either try and do it a third time or make a console that is significantly better than the PS4 and go for the cote gamers throat.

This seems like a great idea honestly. I know a lot of people bashed Nintendo not aiming to be as powerful as the ps4, but it isn't who they are. Their system can do without next gen graphics. I think $150 console (no gimmicks) with their iconic games like super smash bros, mario kart and legend of zelda will do well. Also, keep up with the new ips and do not let up. Splatoon was a great new ip that sold pretty well. Keep making those games. However, I believe the two biggest things nintendo can do is allow multiplayer features on their online network such as voice chat, party system, ect and really push for indie games. 

The only problem with all you just said; is that those things are all one major firmware update away for Sony or MS who Nintendo are going to directly be competing with and who already have a much better footing in the digital space than Nintendo. 

This whole " modern console" thing, based on what you have said all boils down to its OS and digital policies. this isn't 2006 when apple reveled the iPhone and basically redefined a mobile smartphone market that was still virgin territory. What you are suggesting means Nintendo does something in an industry that has players already doing all those things in some shape or form and already with vastly larger fan bases that has taken years to build.

No, if that is the direction Nintendo are going into, then it will make no difference what so ever. Everything you have said could be implemented within a week via a firmware update and a few policy changes. it will be a pity if Nintendo makes that the focus of their entire next gen strategy. They haven't even built up a respectable console network and its been over 13yrs since the introduction of XBL. 

There is nothing new about what you say Nintendo could focus on. And most importantly, there are other players in the same feild that are better suited, positioned and prepared to do all that and then some.  

Make it cheap and accessible; like what they've done with the Wii and DS.

Is it that people don't realize that the game industry is an exact science? 

What do you mean by "cheap"? That they should make a $300 console? Or even a $200 console? Here's the thing. By this time next year, the PS4 will be a $300 console. So if Nintendo makes it " cheap" they would basically be making something that is no more powerful than a PS4. And launching at a time when said PS4 has an install base of over 35-40M. 

That would be a mistake if you ask me. 

The type of audience Nintendo would be aiming at with a sub-$200 device would not be the same audience as the PS4/XBO.

Ok maybe cheap isn' the word I was looking for.. affordable, it is then. I mean, the guys at Nintendo know they can't compete with Sony and Microsoft with their home consoles, so why bother try enter the power race. The reason why they were so successful before was because their unique hardware and software on their consoles. Also, they were priced well from launch. If Nintendo released a $400 console now, with better specs than a PS4, it would tank. Probably even more so than the Wii U.

They have to some kind of feature/gimmick/novelty that makes people go "wow this is different". Agreed that simply have a cheap console isn't enough, the PS4/XB1 will be relatively affordable by next year too ($299.99 likely with a game bundled).

Because Nintendo done terrible job with Wii U, they maked so many bad decisions with that console. So just correction of Wii U mistakes would them guarantee much better sales.

Leaving console market is for them is last option on table, they need to have very serious loses few years without sign of improvement to start consider something like that.

To be honest unless they have a killer idea I'm not sure a Nintendo console can be successful in the modern market context.

They may want to focus first and foremost on the portable, and if there is a second home-only SKU, just make that more of a companion type product.

GameCube was $99 for like half its life cycle and it still only capped out at a rather mediocre 22 million install base. So I dunno if price alone is the solution.