Your airdrop proposal seems very selfish. If you get money for nothing, you cannot value it properly. Not really sure if that would be a good idea.

But I must admit, giving a small airdrop to the active community (let's say 1000 steem for every active steemian who owns more than 1000SP) would increase decentralization by a lot and it would be effortless.
You would have to do it for accounts older than 6 months to avoid people creating separate accounts to get more money for free. And exclude powerups that happened after the announcement and 1 week prior to the announcement.