Can you decide the fate of old idea? assign them as planned or review and if you cannot do it then tag as forbidden or postponed or delayed or cancelled...
5yr or 6yr old idea are still active makes no sense... or does it?
Temporally freeze new ideas from entering and escaping the community.
(call it a travel ban, or a global freeze, whatever)
Why ? Because at first spend time in reviewing the existing ideas (Duplicates + Active), and then please decide them as Planned / In Review or at least Disapproved if they were no future use.
This will guide users and Tableau team to align on same page and correctly understand the priority and show a track of, How Tableau will lead us to Where in the next level.
After finish this tagging exercise then allow ideas to pour in. I think it may be less than a week to cleanup their system. Users can take a Idea Vacation for a week.
Remember unless tableau decide the fate, its so hard to keep waiting forever....
THESE EXAMPLES OF FAMOUS OLD IDEAS SO FAR: