Firstly my Internet has been broken since Monday so forgive my grammar as posting from my phone 

Out of interest what do you think makes a Nintendo accessible?

Some background as to why I ask and wonder this myself 

The Wii was hugely successful partly because it appealed to a wide range of age groups. But it's actually the DS and 3DS that make me wonder. 

My Dad who is now 65 years old has never had an interest in games even though me my brother and all his kids have been acid gamers. Two of us regular day one buyers. He is also terrible at using tech stuff even after he decided it was time to learn and took a 12 month basic computer course he is useless with his laptop and I regularly get called downstairs because he did something and no idea what our how to put it right. He doesn't even know what a Use is. 

One year we had this idea of buying him a second hand DS and got one for £30 picked him a few cross word games and he loved it. Since then as he was getting so much use from it I got him a 3DS XL last Christmas which seemed a good investment seen as his eyes aren't great the bigger screen would be a big plus. 

Again he loves it and plays it most the time. Though not like a gamer who would go buy the new call of duty etc.  He lives his crossword games, the professor Layton series and he even got into puzzle bobble (that ball shooting game) and some Mario kart.

Yet if I put a Vita in his hands he would be lost and give up after mere minutes and say it was cap or to complicated. 

Recently I even had this great idea. After buying my PS4 I thought I can set up my PS3 downstairs for him maybe he would start to enjoy a broader range of games with as there are tons on it installed of varying genre. He can't even figure out how to play a bluray, never mind pplay a game. 

So why do you think someone like him can be so at home on a 3DS yet gets so stuck on anything else? 

Is it the operating system? The game? The controls? Interested to hear opinions 

offtopic: this is why I hated Microsoft original xbox plans with no Internet I wouldn't have been able to pay my xbox since Monday and Virgin tech isn't due to tomorrow >.< no Internet s sucks. And does this predictive text good knows how many times I had to correct words in these posts 

It's the intuitiveness, it's easy to pick up a DS and play immediately

I think its a combination of their hardware design choices (simple buttons - A, B, X, Y, L R) and the simplicity of their games.
Alot of Nintendo games have a very clear premise which is immediately obvious when you start playing the games.

I think its mainly the control scheme though. People will much easier understand "press a to jump" than "press triangle" and in the latter you will just get a response of "WHICH ONE IS TRIANGLE!"

I think it has to do with the games, you said he liked crossword games and puzzle games, which are better played on a DS/3DS because of touch-screen.
And the interface is more vibrant and simple to use/read, just compare the Wii and PS3 for instance.
Maybe he finds the 3DS more comfortable too?

I don't think he's into hardcore games either, and prefer simplicity (ex: Blue-ray player vs PS3 Blue ray player which is different in how you handle things)

I bought him a bluray player for his birthday. He couldn't work and never touched it.it's what I removed to install the PS3 :s

"Yet if I put a Vita in his hands he would be lost and give up after mere minutes and say it was cap or to complicated."

What? Why? He can't use a touch-screen? He can't press on a bubble with the name of the game on it? Okay, if you say so, though I'm not sure what kind of sense that makes.

If someone can't differentiate wich one is a triangle next to an X, a circle and a square, it will surelly be needed much more than easy games for him...

But for someone who has never played games before its much easier to use concepts which already exist, and using letters as labels for buttons is much more standard than shapes.

So they can look at the controller maybe a couple of times and identify "ok, this one is a, this one is b" and get it pretty quickly.

The need to keep checking what button is what with a new concept of shapes as a label will break someone away from the game experience

Brain training was a popular DS game selling 35m units.