A lot of people (at least on GAF) have really blown this whole PS4 RAM thing out of proportion. 4.5/5.5 is still plenty for games, and it's GDDR5, so it's plenty fast. Some Sony fans have acted like this is some sort of huge disappointment, that the (never confirmed) 7GB of gaming RAM didn't come about.
I think the reaction stems from two things:
1) Console war. They want to believe that the PS4 will wipe the floor with the X1 in terms of graphics, and now that the reality has them closer, they don't like it. It's not enough that the PS4 RAM is faster, or that it has some other better component; if everything isn't clearly WAY more advanced than it is on the X1, then it's not good enough.
2) A lot of core gamers out there can't get it through their heads that the gaming world doesn't revolve around them and them alone. They believe that almost every bit of tech inside their preferred console be dedicated 100% to gaming, and that any time or money spent on wooing anyone else is a waste. They will spit venom at any console-related aspect that they perceive will not boost traditional gameplay. Entertainment apps, voice/motion control of UI or games; all are viewed as a waste and as unimportant, because it's not exactly what they want. Very much a "Stop liking what I don't like" mentality.
At the end of the day, the PS4 is a fine console with plenty of RAM for games, and no one is really going to suffer because Sony decided to play it safe with RAM allocation for their OS. For Xbox gamers like myself, I don't think this really means much; the only difference I see is that the Xbox One should have an easier time holding up graphically in comparison to the PS4 down the line.