I don't think Tom is defending sync;sync;sync since he points out why it doesn't offer any protection... he is offering an anecdote on why people do it as a reflex but shouldn't expect it to work.
[He points out that on only some systems does the second sync wait until the first one is done. On those a sync; sync; sync would write.. but on others its only to make you feel better since well the kernel sublayers and the hardware below still have to decide if they really are going to write out the data or not.]