Zawinski is a nihilist crybaby who thinks anything he didn't create is garbage. He can be amusing for a while, but then his whining gets tiresome. While he did participate in the founding of Mozilla, he abandoned it when things didn't go to suit him (i.e. it actually became open source).
He's also a hypocrite. He wrote xscreensaver, which is used on just about every Linux distro that ships with X. He maintains rigid control over it, frankly because he loves being considered as a Linux insider. What a goober.