This is pretty much what I didn't get: only a very small percentage of those critical of the original post would have "made their fortune", only some subset of

This is pretty much what I didn't get: only a very small percentage of those critical of the original post would have "made their fortune", only some subset of them during a bubble, and a further subset because of the bubble. Attacking a tiny fraction of your audience that are easiest to criticise is convenient, but not particularly compelling. What about the other 20-somethings that joined the criticism? The ramen-subsisting founders using a flat as home and office?