Sure, when you look at the worst-selling Nintendo console ever it seems like going third party might be slightly more profitable for them. Now tell me Mario Kart Wii would have sold ten million more copies as a PS3/360 game.

You also forgot to factor in the increased costs of developing on two or more platforms at once.

When/if Nintendo is in a dire situation like SEGA was, it's already to late.

Ya, I don't see it. Sorry but nothing on Sony or Microsoft has shown me Nintendo could be as successful as they can be on their own hardware (if done correctly). Mobile Platform works with Nintendo, Third Party Publisher (In terms of non mobile Activity) like EA, Ubisoft or Activision, no not as much. 

No, potentially it's a lot more profitable for them, even if we presume their next platform is a moderate success (N64 level, 30-35 million sales). If Nintendo, in some magic way would be able to even come remotely close (70 million +) to replicating the Wii's success, then sure, going third party wouldn't benefit them.

I didn't forget to factor inthe increased costs of developping for two or more platforms at once, but I don't really know how much it would cost to port a Nintendo game from the PS4 to the XBO or vice versa.

That's about right, give or take a dollar or two. At least it was when I was working retail.   Of course, that's 15 dollars in margin, not profit. 

Then that is a non issue really.

Total War, Football manager. company of Heroes and Persona are all from companies they have purchased and will probably drag to the mud woth them. It has already been happening with the european studios and its only a matter of time until ATLUS gets affected aswell.

Valkyria had 1 good game. The series then went portable and died. Yakuza, really isnt as good as you make it pass. It has great cut-scenes and main story, but the gameplay, be it the combat, the mini games or the numb quests are extremely boring. I can atest to that as i have just beaten Yakuza 3 and 4 recently. I am pondering just watching Yakuza 5 on youtube because the gameplay, im sorry to say, isnt good. Also, lets be honest, the series has been in heavy decline and probably ended with the recent entry Yakuza 0.

So, SEGA themselves really have nothing left. They are mostly a Japan only company these days as far as consoles are concerned with no sign of recovery. All they do have is companies they have bought in the meanwhile.

Quite honestly i would have prefered if they bankrupted and their IP's had been auctioned instead of just having everything going dormant.

Thats the point isnt it? Some publishers are just leeches. Electronic arts is the same... except they have managed to stay afloat with the destructive strategy due to the sports games.

Yes but the point is that Nintendo is in nowhere close to that situation, there is a pretty large middle ground between Sega in 2000 and Nintendo in 2015, like I said u don't just bail out on a market that has historically been very, very profitable for u with no guarantee that it will benefit u. Nintendo posted 3 years of losses because of making very large mistakes, if they fix those mistakes yet still are posting losses than maybe u have a point but as of now there is no reason for Nintendo to go 3rd party.

I really think Nintendo will go with a unified platform so that software sales aren't tied to a small userbase. Let's say the console sells 10-20 million and the handheld 40-80 million, that's a combined 50-100 million install base to sell to instead of 2 individual smaller markets to sell to.