The premise of this thread is easily testable.

I read Steve Jobs missive and decided i ought to test his thesis. I have two identical MacMini's at home, so I loaded Flash on one and Java on the other to read the identical clip. The Flash one took 243 seconds from the time of download beginning to play commencing, and had two brief halts during playback. The Java took 125 seconds for the same download and had no halts on playback.

Of course anybody can make a similar test. It seems fairly obvious that Flash is buggy and old-fashioned in comparison to alternatives. I conclude that Mr. Jobs may be irritating but he's apparently correct.