I can't agree with this.
People bought the PS2 at launch and its launch library was a fucking joke.
The PS3 stuggled because of (a) supply issues and (b) FIVE-HUNDRED-NINTY-NINE-DOLLAH.
The PSP also enjoyed fairly good sales and lots of hype despite a rather thin launch library too.
The PSV is a handheld launched a year behind its biggest competitor, and at a time when dedicated portable gaming systems are seeing more competition than ever. Not just in the context of gaming on other mobile devices, but more simply...being able to do other things with your on-the-go time. People may not be gaming on their phones, but the fact that most have smart phones at all is a big difference from 2005. It means they're talking on the phone, texting, checking facebook, taking pictures, updating their twitter, browsing GAF. Point is, they're busy enough with other things they can do on the go to make them not feel a need to game at all. Given the target age for the PSV is in the 20s, it makes even more sense that they'd struggle. The number of 20-somethings looking to game a dedicated device on the go instead of do something else with that time is getting smaller.
Ultimately, I think the PSV will be fine, but people need to amend their expectations. Or, those that expected this device to equal or surpass PSP numbers will have to. If the PSV meets 50% of PSP lifetime sales, I'll be impressed.