appears to be a pretty sharp guy: he works for Google; he's been using Unix for some fifteen years; and he's a programmer with several cool projects under his belt, including the DWM-like LWM (Light Window Manager).
He's also written a series on Desktop Linux suckage and it's worth a read, if the reader takes it with a grain of salt. He's disabled comments on the blog, which is probably a good idea because he's going to tick quite a few people off.
My biggest problem with the series is that it basically boils down to Steve Jobs not running the Gnome Foundation from a point of benevolent dictatorship and Ubuntu not being OS X. In addition to that, despite being a programmer, he gets some pretty basic information wrong.
Regarding Gnome development, he says "What we actually have is the GNOME HIG, GTK+, and C. Oops. ... The three serious contenders for an alternative to C, namely C++, C#, and Java, are probably all too politically contentious to succeed without causing serious upset." He completely ignores (or doesn't know about) Vala, which is Gnome's C#-like choice for future Gnome development.
He also regularly conflates Linux-based OSes, Gnome, and Ubuntu, which muddies his argument greatly.
Still, if you understand who is responsible for what in the Linux OS stack, and you can read with a critical eye for logical mistakes and bias, there's a fair amount of useful bitching going on in there.
At least it seems sincere, which is more than I can say for the Linux Hater blog.
p.s. His LWM project seems a little ironic in the perspective of his usability requirements for the Evolution PIM. Hint: the configuration is chosen at compile time.