The all-in item in Fnord'st list is there to say that its never a good idea to be short stacked. If you get that way, you should buy more chips, otherwise, if you get a big hand you won't be able to maximize it's value.

e.g what if on the next hand you flop a full house, and there's 4 other people liking their hands too, but you had to go all-in on the flop. You could have made more, but .....

In other words, you should really always have enough chips in front of you to cap the betting on every street.