I think that this is a very interesting kind of problem. I think a lot of those active accounts choose not to vote for witness for a purpose. I think that if witnesses want more votes, they'll need to find a way to engage those users and earn those votes.

Personally, I only upvote for a handful of witnesses and that's because they've earned my vote on a personal level. @someguy123, @ausbitbank, @aggrooed, @teamsteem, @klye, I've talked to these people personally, and have worked with them personally. So when a witness gets a vote from me, that's because they've done something in my eyes that deemed them vote worthy, or if I feel that they really are doing something good for the community.

That's how I vote for witnesses anyway. But I'm just a tiny minnow.