Actually, it is. No sense in defending Sony for the sake of it.
That isn't what I'm doing.
Market dynamics are very complex and consist of many, many factors. It is very doubtful that a relative detail [and don't get me wrong, the proprietary memory cards are quite inconvenient to me, an existing widely-supported format would obviously have been way preferable for me as a consumer] would have a signficant impact when the handheld market [for a handheld that isn't catering that much to family-friendly appeal] was already very small by the time the PS Vita launched to begin with.
It may actually even have been beneficial from a business point of view of SCE if the extra revenue and profit from the proprietary memory card offset (with surplus) the potentially lost revenue/profit the extra sold PS Vita systems to consumers who didn't purchase PS Vita system just because of the proprietary memory card format, would have generated.
Compare the PSP to the Vita. The PSP was a massive success - and the fact that it had the ability to use TV out with a $15 cable, had a less obscure proprietary storage format (shared with things such as cameras) that free fell in price after a few years, and all the first party and third party titles... It goes to show that yeah, it does, historically, work better than the Vita's method.
Not to mention Nintendo's platforms since the DSi having proper SD support.
Different timeframe, different market conditions, different results
Also, the first dude - he wasn't saying you were "wrong" because the PS Vita has less sales. He's referring to the fact that the PS4 has had everything going for it: great support from the west and east, great first party support, priced well, etc.
The Vita was priced a tad high at launch, the memory cards are stupid fucking expensive, and support from everyone except indies and 3rd party Japanese games aiming mainly for the otaku audience have died off.
Some of those are subjective factors.
I can say for me, that the PS Vita for €250 is better value than a PS4 for €400. (or even a PS Vita for €300 vs. a PS4 for €300; I'd still consider the PS Vita to be a better value proposition)
No one is saying the Vita is a "bad system". What they're saying is that the average consumer can think of a laundry list of things wrong with the Vita (if they know about it), but would struggle to do even close to the same for the PS4.
I seriously doubt that. I haven't done any kind of research in that regard so I may very well be wrong, but I think that it is more likely that they'd say things like "I already have a phone in my pocket that plays games", "I'm not interested in playing on a tiny screen", "My kids/ younger nephews/ younger brothers/sisters play on 3DS and mobile phones already, but I'm not interested"
It would be related to the device from a conceptual point of view not appealing to a large audience (and thus likely to not appeal to the average consumer), rather than issues with the quality of the device.
I mean, it might sound far-fetched at a glance, but I think the it would be a bit the equivalent of asking what an average consumer thinks of a prosumer-level camera/camcorder.