Really interesting topic! I've also has something similar in mind..

The one big thing (that I'm starting to really grasp) about having more SP is having more to give, and there are soo many people on the platform who could benefit from a "bigger" upvote, especially those living in less fortunate places where it could genuinely replace a living, and help feed their families.

I'm using that as my biggest motivator at the moment to want more SP! And as you say, it would also help encourage people you get on Steemit to stay :)

I'm sure you'll get your $1 upvotes in no time!