their entire argument is "SSDs cannot replace HDDs, since there isn't enough of it to meet worldwide demand, and it will require 250b to build all the plants needed to produce it"
While SSDs will not totally eliminate HDD in 2011 for the reasons he stated, to claim that this means that the tech is "doomed" is ridiculous. Technically it will remain niche in 2011 (for exactly that reason), but its nothing to do with doom.
In fact, this demonstrates more of why HDD tech is doomed rather then SSD... Such scarcity of a higher grade product means higher prices... if you had 5b to invest would you build an SSD plant or an HDD plant? the obvious answer is SSD plant since the ROI is better, you can over charge due to scarcity and the world is buying it due to being superior tech.
Over time HDD plants will shut down to be replaced with SSD plants.
This is similar to what we saw with LCD technology... at first they couldn't meet demand, but overnight development of CRT dried up. People saw the writing on the wall and technology transitioned.