That particular quote was a quick estimation to show that it could be done by nodes at all. The fundamentals still required specialization over time. Regular users were intended to "just be users" and not run anything but simplified nodes.

Secondly it would seem growth in RAM has kept up rather nicely, just as Satoshi expected.

With the advent of fiber, perhaps to be replaced by even faster and wireless devices, (and VR enviroments boosting demand for memory), I think we can expect quite the ride in the coming years. Not that any of this means regular users should be running full nodes at this point.

Here's a quote just for the sake of providing a source for my claim Satoshi ever said such a thing. (And btw that's what he was frequently called by others, the full name was rarely used)

Only people trying to create new coins would need to run network nodes.
At first, most users would run network nodes, but as the network grows beyond a certain point, it would be left more and more to specialists with server farms of specialized hardware.
A server farm would only need to have one node on the network and the rest of the LAN connects with that one node.

From the Crypto mailing list. Anything else was, in his own words, "a gentlemen's agreement".