Signature campaigns are promotional campaigns that have nothing to do with the market and Bitcoin's price in the first place. They are run in this forum, to promote certain services and platforms and the management of those services and platforms pays money for that. Managers choose people based on their posting habits and how often their posts get merits because those who are paying money to get their services promoted want quality.

A person making useless posts all around the forum while holding 2 bitcoins in their wallet wouldn't benefit the service that they are promoting in their signature because people will barely read their posts and most of their posts will likely get reported by members and deleted by the mods. This is why, people who make quality posts are accepted in signature campaigns because they right logical and constructive posts, and such posts tend to have a higher readability percentage.

So I don't see any reason why a long-term Bitcoin holder deserves a place in a signature campaign only based on their holdings when what's important for signature campaigns is a user's performance in the forum and not in the market.