It's not about spec. Switch despite having low spec compare to even Xbox One original it can run modern games with a lot sacrifice and cut down graphic (resolution , effect ) and frame rates. The problem is on the developer and publisher hand, and also the market (is there anyone willing to play multi platform games on Switch) and if there is benefit or not on porting the games to Switch.

This is the same case with Wii , where developer create a different version to port, or even downgrade like crazy to be able to port to WIi. Wii is a very powerful console compared top Xbox original and Gamecube but it still not on par with PS3 and Xbox 360. I hope EA can make a different version on Switch or some publisher willing to bet on Switch to create another version for switch. Of course this will add extra money, resource to the development.

It seems Wii and Switch are indeed trying to target different market then Playstation and Xbox. It has benefit and also bad side . And Nintendo seems very comfortable with this . Switch and Nintendo platform can support other platform such PC, console (PS and Xbox) , it can co- exist for both . So probably many third party and multi platform publisher thing they don't need their games on Switch because many Switch owner has already has PC, PS and Xbox.

I'd say that the job posting memes that they are considering bringing a game to switch. It doesn't necessarily mean that they are going to do it though. If they're hiring for someone for a position that will take years to play out, they certainly would want to leave the door open to a switch version of whatever game this is about.

* Mass Effect 1, 2 and 3 is Unreal Engine.
* Dragon Age: Origins and Dragon Age 2 used the Eclipse Engine and the updated Lycium Engine.
* Mirrors Edge used Unreal Engine.
* Command and Conquer: Red Alert 3, Uprising and Command and Conquer 4 use the SAGE 2.0 Engine.
* Crysis 1,2,3. - Variants of CryEngine.
* Medal of Honor: Airborne. - Unreal Engine.
* Titanfall 1, 2. - Source.

You also have SimCity, The Sims and so on.

By porting over Frostbite though... Suddenly the more modern releases of Plants vs Zombies, Battlefield, Medal of Honor, Dragon Age, Mass Effect, Mirrors Edge all become  possibilities... Visually they should be a step up over the Xbox 360/Playstation 3 variants, but also a step down from the Xbox One.

What API is that?
And you do know Sony, Microsoft and Nintendo are constantly improving their API's and sometimes add entirely new ones?