What they fail to realize is that these linear charts plot a $5 change the same distance when Bitcoin is $10 as when Bitcoin is $4000. Yet for Bitcoin to go up to $15 when it was $10 it had to increase in market cap by 50%. For bitcoin to go up from $4000 to $4005 it doesn't need jack squat, it's a rounding error.
A better view of Bitcoin's price is in log scale. Here you can see that the growth is steady: http://i.imgur.com/R9yQ8Dk.png
There is nothing special happening now, as there was nothing special when it went from $5->$10, $50->$100, $100->$200, $500->$1000, $1000->$2000. People just want them, and they are a finite resource.