I'm guessing his point is that "4 GB" is a big problem on a phone.

Yes it is, but his number was an exaggeration in the first place.

There are hundreds of millions of phones running Java today, what does that tell you?

The point is that memory still matters, not that Java is inherently a problem. You're shifting the goalpost here - earlier your claim was that 4GB is not a big deal since we can just buy more memory, now it's that 4GB is a ridiculous number anyway.

It's not if you meet one of these typical "don't do any premature optimisations (even in the design phase of my data structures), because some important CS person said so"-designs. There's all too many programmers who think they should never have to care about hardware anymore.