I feel like blaming how people comes and goes to OT to how denizenship is handled is not a right approach.
The reason why activities decreased is because the quality of threads and interactions have gone down through out the months/years. People are less likely to go back to OT when they have no attachments or any meaningful interactions on OT.
Until that problem is solved or dealt with, changing the denizenship requirements will not change how people posts or their attitude on the forums.
Sure, activity on OT might have a boost for a short period, but it'll eventually go back down when people are bored or that they realized that the title of an OT denizen literally means nothing.
Not to mention this goes against why abraker started this denizenship thing in the first place. It was meant to be a reward/acknowledgement for meaningful contributions to the forum, no matter how brief it was.
The change you're proposing will change the very nature of this and will turn denizenship into an elitist title that people have to work for and prove themselves for and yes, some people are desperate for internet clout and in that way, you'd get more activities on the forums, but personally if you ask me, the people who only interacts with a community ONLY for an "elite" title and bragging rights will not bring good or meaningful contents to it, nor are they very fun to interact with on the forums either.
I'd much rather we have less denizens but they actually know and interacts with each other in a meaningful way than having more retards who would just spam the forums for a few months so they could get a meaningless internet made up title.