The actual source mention this:

"Specifically, one software demo included with the kit crunches so many polygons that it's currently impossible to run at 60fps using a current-generation Intel (we're assuming a Core i7 Skylake) CPU and a nearly top-of-the-line graphics card (no specifics provided, but they probably used a single graphics card)."

You are right, they are assuming specifically that CPU and not a GPU, interesting.

Well considering the PS4 & X1 are absolute disappointments for me in terms of power (especially CPU power) I should hope so.

Not with Nintendo, again, like the Wii U.

Uhh, then what would be the point in handing out hardware that couldn't be used for realistically prototyping software ? 

I'm pretty sure Nintendo already said that horsepower will not be a characteristic of NX. Huge horsepower demands technology, and they want the console to be cheap.

Like I said guys look at this NintendoForum website. The biggest thread in their forum is one with like 33 replies.

To say this source is dubious would be putting it mildly. A 13-year-old with a Twitter account could have made the same post.

No, the problem with this is that they are judging the hardware because a demo. For example, the GameCube had a demo (Rebirth) and no game released on the console looks as good as that. Let's also remember the demos on Wii U. We don't know how are the games going to perform and until we hear "Mass Effect Andromeda is running at 1080/60 and no current console can match that" this comment is not exactly confirming anything outside of Nintendo upgrading the specs.

If the NX turns out to be a complete powerhouse then Nintendo might just be able to compete for an entire generation and a half with a single console. Man, I really hope that the NX doesn't just settle for PS4 and XB1 standards.

It will be at least 1,5-2x times more powerful than the PS4, if not it wouldn't change anything. I'm more interested in the power of the handheld part more.

It doesn't need to be more powerful, but at least on par.