Actual size is of some importance (lets you fit more on a screen, etc.) but generally I agree that one should emphasize actual improvements that <i>happen</i> to be shorter, over the explicit goal of being short.<p>I think of Twitter as an example of the brevity problem.  On the one hand, the size limit has resulted in some very neat tweets that manage to say a lot in a little space.  On the other hand, we ended up with things like super-short URLs that completely remove any hint about their meaning in the name of brevity.  One limitation managed to both improve and damage at the same time.