Your scores have absolutely nothing to do with your earnings. Hubpages doesn't know how much you earn - your adsense ID can get you involved in your own website, and a dozen or more other websites that run Google Adsense ads on them.
I have no idea how hubkarma is calculated. I honestly don't know how hubscore is calculated - but I have some very good ideas about hubscore. Let me tell you about hubscore and earnings though, okay?
I've had a hubscore . . .my author's score up as high as 97 - that's my highest. I've had it up to 96 a couple of times, and it's been around 94 or 95 most of my time on this site.
So far as I know - my score has always been higher than the score of a hubber who may, or may not be here anymore - and his name was/is "Misha."
Misha was making a hundred bucks a day from Adsense. I promise you that I've never, ever been close to that - I've never been even in the same league.
So your author score has nothing to do with earnings. I believe that your author score has more to do with your participation in the Hubpages community than anything else.
If you want to make money on hubpages - then you can do that, and you can do well at it; but it's all up to you, how much you want to learn about how internet marketing works, how good your writing is, how much you want to improve that - and especially, most importantly - how good your hubs are in comparison to other works on the internet in the niches that you write in.