As much as haters want it, no, Nintendo wouldn´t be more profitable as a third-party developers only. First because Sony and MS fans would never buy Nintendo games even on their platform of choice. Nintendo has its own audience and it would be just a smaller company with smaller profits

Constantly selling 20 - 30M units of games would be much more profitable than 6M one gen, 25M the next, and 4M the next. We are talking about games that sell better than GTA and COD on much lower budgets. Retro Marios, 3D Marios, Mario Kart, Pokemon, all these titles could sell 20M plus, may even see 30M or more in some cases. Those kind of sales would outweight the difference between 1st and 3rd party royalties.

Your question is commonly posed by trolls and people with axes to grind, but I will presume you are honestly curious yet ignorant.  Joe the Bro has given a pretty good answer.  If you missed it, here's the short version:  Not only does Nintendo profit on its hardware, but it also gets significant cuts of the sales of other publishers' games on their consoles, while keeping the cut they would have had to give Sony or MS if Nintendo published on their consoles.  The increased audience isn't worth it.  

Absolutely not right now! Nintendo would probably have to go below a 10 % hardware market share in order to even consider going third party from a business perspective.

However, I wouldn't rule out them going semi third party either by making games for smartphones or by licensing some of their intellectual properties to software companies making smartphone games.

Let's hope it never happens. Nintendo would probably end up focusing a 100% on their biggest franchises that are sure to make a profit, while neglecting other franchises altogether. Not that big a difference you might say, but we would.t see any Endless Ocean, Punch Out, Sin & Punishment, Fatal Frame, ExciteTruck, F-Zero or Wave Race titles ever again. We would see a lot fewer games.

Look at Sega's output after they went 3rd party and compare it to their games before that.

Oh look, the 124352th topic on Nintendo going third party. Man, Nintendo games must be even better than I thought, since soooo many people are dying to play them on other consoles hahaha. 

Oh and to answer your question, absolutely not. Nintendo going third party would be death for the company, or at least of its soul. Just ask Sega.

I can't see how they could possibly be more profitable considering the billions upon billions they've made off of hardware over the years.

Also, English is not my native language. Could you explain which answer in the poll means yes and which one means no?

For starters there are plenty of other alternatives to releasing titles on Microsoft and Sony platforms. But if they do go that way the platform royalty payments are nowhere near 30%. The highest estimate I've seen is ~11%, and that figure is lower for full price titles from large publishers. Nintendo could avoid royalty payments entirely by selling their titles exclusively on one console provider.

They'd lose the royalty payments they receive of course but that would be offset by the massive savings by cutting R&D and losses made on selling the console.

When people ask this question, I often think of Sega. If anyone remembers, Sega did not want to go third party. They had to. They had no choice. I think Isao Okawa understood the consequences of Sega going third party, even though he knew it would have to happen eventually. Nintendo is not in that situation and most likely won't be In that situation for a long time. Culturally, Sega was no more. Without their own hardware, they lost the competitive edge they once had. People left and all Sega is now is just a name. I think Satoru Iwata understands this better than just about any stock owner.

Having a larger market to sell to would actually encourage Nintendo to produce those games. Currently Nintendo has to focus 100% on their biggest franchises as they rely on popular software to make huge profits to cover the losses incurred by selling the console. Look at the Wii U's current lineup, it's incredibly safe bar The Wonderful 101 and you can be sure Nintendo won't be making a mistake like funding that game again. If they were third party they'd be safer making new titles as they can sell to a huge market and they won't be relying on games to sell their undesirable hardware.

The Sega situation is in no way comparable. They were a company that went almost bankrupt and then went third party. Of course their output declined, they had to cut most of their devs as they ran out of money persisting with a failing hardware division. Nintendo going third party sooner rather than later would avoid this exact scenario.