Let me preface this with a run-down of the reputation system:
Users on the site can cast up- and downvotes and accept answers on their questions, each giving or taking reputation to or from other users and themselves. An upvote on an answer gives the answerer +10 reputation, an upvote on a question gives the asker +5 reputation, while downvotes always yield -2 reputation for the poster and, on answers, -1 reputation to the downvoter. Accepting an answer also gives the asker +2 reputation and the answerer +15 reputation. On top of that, there are bounties, which transfer reputation directly from one user to another, with no net gain or loss (that is, if the bounty is successfully awarded; otherwise, the bounty is lost at least partially).
Reputation, then, is used to unlock privileges. Some if not most of these privileges are vital to "community moderation", that is the community (a set of at least 2 users, usually 3 to 5 even) can actually use this privileges to moderate the site on their own, without the need for designated moderators. They can approve and reject edit suggestions, vote to close, reopen, even delete posts, and act on certain flag types at certain reputation thresholds - this helps keep the site clean and organized. A full overview of privileges and how they work in detail can be found in the /help-center in the /help-center/privileges section. This system allows the site to be run by community consensus instead of a restriction to a small amount of moderators. Moderators, on the other hand, can do all of this and more without the need for reputation or other users to make the same decision. While this is sometimes necessary, it should not be the main route for site moderation.
While low-reputation users can cast flags and bring posts to the attention of those that can act on them, it's down to those users with higher reputation to make the decisions.
This brings me right to the problem:
Low Voter Count
As I detailed above, reputation is crucial for any Stack Exchange site, including Ask Ubuntu. A healthy site generates a reasonable amount of reputation for its users, giving users the privileges they need in order to participate directly in community moderation. Ask Ubuntu, however, currently has a very low votecount, which results in a low amount of generated reputation in relation to the amount of users and posts the site has. Not only is this psychologically a burden for any expert (there is little material gain from helping people here), but it also actively hurts site moderation.
Users that wish to help with site moderation are forever stuck with low reputation, while those that do have the reputation are facing a near-unsurmountable mass of actions to be taken. Reviewing and the actions associated with it are limited per day - and depend on the high-reputation users' willingness to act in the first place, while the mass of low-reputation users can flag far more posts than can be handled effectively.
This is an issue that no amount of moderators can fix. If people don't vote enough, help gets no return and the site easily becomes cluttered - these factors drive experts away and leave even more unanswered questions. This is also an issue that no single user can fix. While everyone is encouraged to cast their up- and downvotes until they hit the vote cap, there is little motivation to do so when the effects thereof are so miniscule.
With that said, this is essentially a plea for more voting activity: Everyone should vote more frequently.