A lot of people didn't expect it to happen this early and especially with cross-generation games. When next-gen starts proper it's going to be another round of fun!!
The reality is a lot of people assumed wrong because a lot of people just don't understand technical specs - not being arrogant BTW just noting that's the problem here.
The situation is one where the bulk of the audience is not informed enough on what really makes a difference here - I've no doubt casual gamers will assume they're the same spec because they each have 8GB of memory - and to be fair why would they understand the difference in memory type?
Hell I still see people post or claim that the 360 had 512 MB of memory whereas the PS3 only had 256 MB because they miss-understood the PS3 memory architecture.
What's happening is evidence and word of mouth is passing on the message in an understandable way and the many non-technical folks who just made assumptions are finding out they assumed wrong.
Speaking as someone with a Computer Science Degree and a former programmer who regularly gets calls from my gaming friends for technical support and still finds that most of the time they've plugged something in the wrong way BTW.
I guess we'll see threads like this for a while until the reality that this gen the power gap is much more significant and real fully settles in.
As an aside I'm curious to see what "slightly" translates too given Kojima would want all versions to sell well and is hardly going to note anything else - but also wondering why if they're just slight he'd bother mentioning it at all? I'm guessing slight is still going to be something that can be noted - be it better resolution or frame rate or something like that.
Of course he could just be very honest guy (and I mean that honestly myself!) and noting there are some genuinely just minor differences.