I know what you mean. I've seen teams treat a backlog's growth as being a root problem. They responded by closing issues with the explanation "We probably won't ever get around to this" or by creating scripts that will auto-close any issue after a set period of time.
I'm still on the fence about whether this is productive or not. I guess it depends on the team's context. A growing backlog indicates strong demand for features and/or many defects being found in the product, at a rate which outpaces the team's ability to respond. My instinct is to make changes to any part of that system but the backlog itself, since it is real data with real value. My strong opinion weakly held is if you manipulate this data, you're just putting blinders on.