Personally I don't think the issue number is a problem. Other metrics are healthy, number of bugs is low and code churn are high. The only reason that we have so many issues is that we're about half way through a major project and accelerating. So we're getting more core users and developers but we have a deficit in issues fixed as it takes less time to learn to use the server than to get up to speed developing it.
Have a look at our commit activity graph
Have a look at our commit activity graph