The Switch IS using the Blue Ocean strategy. The hybrid nature of it puts it in a market of its own which is largely unexplored and untapped. Nintendo is creating the demand for such consoles, and it's evident now that there's a gigantic amount of unopposed growth potential.

It’s also more “casual” since it is designed for more relaxed play, and makes it far easier to play shorter game sessions with greater convenience.

As a note: The Casual Games model/category, however, refers to games that are played for a few minutes a session, but over long periods of time (potentially years), like Candy Crush, Clash, and Fire Emblem Heroes.  Neither ARMS nor 1-2 Switch are designed this way; one's a fighter, the other is a party game. The term was coined by Nintendo to describe the play style of Brain Age series.

You're confusing the Blue Ocean strategy with the specific Blue Ocean that was targeted by the Wii & DS.

Switch is definitely Blue Ocean.

Forget the word "casual", it doesn't apply, that was fake hyperbole from detractors. Casual gamers existed before, they bought PS2s and whatnot.The real term is "new gamers". Do you honestly think making these new gamers flow into Mario wasn't a plan?Why do you think they made Super Mario Run for iOS?

It's definitely Blue Ocean. Not only from a differenciation lense, but certainly in terms of audience. So you can say it's disruptive too..

Not sure if they are tapping on blue ocean or not, but being blue ocean have nothing to do with casuals.

But I would be glad Nintendo keep titles that their core fanbase like.

You lost me at Arms being a blue ocean casual game.

As part of their core fanbase I have to agree.

But that alone isn't successful, exhibit A: WiiU

You're taking the current top standing that amplifies the recently launched titles .
Look at the monthly totals we have from NoE: http://gamrconnect.vgchartz.com/thread.php?id=232734

ARMS was second in June, and we are missing the launch months which could have 1-2 Switch doing well.
Switch eShop in itself has a nice mix of titles and genres, but Minecraft and Sonic Mania did good during the summer.

Yep, neither "pure casual" like Wii (that dropped very fast and sold few SW) nor only hardcore like WiiU can keep a healthy platform. And that is the good part for Sony that having 3rd parties it can tap all markets. Seems like Switch will be able to do it from having all Nintendo games on it instead of split userbase plus initial good support from 3rd parties.

and it was marketed the exact same way as splatoon

Agreed.