I perfectly got what he is saying. Not even Nintendo could have been successful with a $250 handheld beyond the short term. Expecting the PSV to do well at $250/$300 if only it had the right games coming out is pretty much the same as believing the PS3 could have been a huge hit at $500 or more if only Sony and third parties got out all the big hits in time. As long as price remains a barrier, you cannot expect massmarket penetration; and most people aren't willing to suddenly pay more than their norm for a gaming system when they know that the price will eventually come down.
Fair enough. To begin, your comparing the 3DS' Y1 against the PSV's upcoming Y1 is not a fair comparison. To explain, here are scenarios where Sony cannot deliver on big guns (sorry), while Nintendo could have. If you blame the 3DS' underwhelming sales only on pricepoint, you'll have no way to ensure it wasn't due rather to a lack of big hit games, or at least a mix of both pricepoint and big hit games. Put it this way: At 250$, with no big hit games, who will bite? In other words, you're missing the scenario where the 3DS released with big guns.
Now why did the 3DS launch fail? The 3DS did not get big guns at launch except for Nintendogs which, granted, is a massive seller. However, first and foremost, it appeals to an audience where a lower pricepoint works (the casual, female and elderly). Now had 3DLand, Mario Kart and MH released when the console was at 250$, in all realism, I can't see the sales results being much different from what we saw holiday 2011. Or, to be more fair, had the 3DS launched in holiday 2011 at 250$ with those hit games, I would've expected similar results. However, since Nintendo wanted to penetrate the market sooner than holidays so as to ensure momentum, and since big guns shouldn't really be released too far from holiday season, the big N was in a catch 22 priced at 250$. Even at 200$, they wouldn't have generated the interest to ensure 16mil unit sales (which ramped up as of August due to pricecut). Ultimately, they should have released the console at 200$, released lots of casual titles and important retro franchises (such as 2D Megaman and 2D Castlevania) for it to ensure a measure of core, then come holiday 2011, launch all the big guns and stay at 200$, projecting a 10Mil unit sale for the system. Thus, they would've guaranteed a solid pricepoint for the console throughout its lifetime, and alienated neither casual nor core (no worries launching some casual hits at launch, it's a launch).
Now the PS3 at 600$ is a 300$ increase over regular console prices. With a 250$ pricepoint being an 80$ increase over regular Nintendo handheld prices, I'm not sure this is a fair comparison. Next, Sony does not have the hits Nintendo has period, bar Gran Turismo. (See LBP Kart thread) Assuming Sony could have Mario, MH and Mario Kart, maybe its success would have been much greater despite the staggering price (even 500$ as you suggest could have made it possible). People buy the iPad at 400$, of course they can do alot with it, but strong tantalizing apps sell hardware especially if the IPs are properly handled.
Bottom line: Nintendo needed to reduce its projection and change strategies for Y1. 10Mil versus 16M is not a big deal, devs will support it at 10Million units, it didn't need a 16M userbase Y1. Focusing on casual titles at launch to herald the runner-up to the DS and encouraging 3rd parties to release their equivalents of NSMB, and at a more reasonable casual pricepoint, this should have held the 3DS up for the first half of its Y1, until holidays where they could launch the big guns.
Ultimately, pricing and game leverage are two ingredients that if properly managed can be optimised to sell maximal volumes. At 250$, at holiday season with big hits, the Vita could sell in droves, but that's not happening; big hits are a Nintendo thing. The Playstation brand sells on variety and long-term, not on explosive hits.