Nope. They've been smarter to stay away from it as well. MS doesn't know how to create mascots themselves so how could they keep a handheld running? Nintendo kept their handhelds going on pure first party until third parties could catch up.

I honestly think this is a bad argument.  The 3DS and mobile phones may share some of the same market, but they aren't IN the same market.  Try to think about what that means.  It's like saying how many PC's and laptops are sold every year and compare it to home consoles and say "no one should make consoles." 

Even though there are a lot of people gaming on mobile phones, almost none of them dedicate that much money into it.  This is why the mobile phone market does not have the kind of quality you find in your handheld console.  

Look at how horrible Vita sales are and imagine how much worse they'd be without Japan because that is what the sales of a Xbox handheld would be like.

MS should treat mobile windows devices as their handheld platform. With that said, they need to put quality exclusives in the Windows Store.

The dedicated handheld market is not niche, lol. Last generation handheld consoles, which consisted of DS and PSP, sold over 210 million units and huge amounts of software. Lots of games sold well over 5 million copies and some even over 20 million. These games would typically retail for about $30-$40 each. Nintendo games especially would sell this well and still retain its launch value.

PC sales far surpass that of home consoles, some people buy PC's specifically for gaming much like some people buy iPhones specifically for gaming (lol, not true but for the sake of arguement lets pretend). So home consoles are niche too right?

PC's aren't dedicated gaming machines, if they were there wouldn't be 100's of millions of people buying home consoles.

Now switch PC's with iPhone then switch home consoles with handhelds and you have yourself a proper analogy.

Not to mention that although iPhone/iPod sales are tremendous, a big portion of people rebuy each edition that release every other year.

I have so much more I wanna say but I won't bother, I will just wait for the responses that may never come. So oh well.

I think all of those device are or were selling better than Vita.

Personally I don't think the handled gaming market is worth getting into just based on how horrible Vita is doing.

This. You said everything. Also, you need to consider that the people who buy high-end smartphones or high-end PCs are the real niche. Those 500m+ smartphone sales are not made only by iPhones, eight-core Android phones or high-end Windows Phones, in fact, they are mostly made by those low-end 800mhz single-core Android phones who can't even run the OS nicely, let alone any games, just like not every PC sold has a high-end Intel/AMD processor and a high end graphics card.

Just leave handhelds to the professional, Nintendo.

No. Both Sony and MS should stay out of the handheld market. Their games do not have the charm or weight to warrant buying mobile versions of them imho.

To be fair I am still rocking my Zune HD and it still works great. I love the UI, sound quality, and OLED screen, it really was a great device and its a shame it never caught on.