You're only partially correct; SD May be topped out at 20 but they have to compete with the handful of other level 20 guilds for the top spot. And it matters to guildies because it gives them a sense of accomplishment to help out. Even topped out; I often like to compete in-guild to show my support.
No doubt it may be broken tho. Let's get a fix - THIS IS IMMPORTANT when you take away another feature that gives a player a feeling of accomplishment.