Well, although FAQ explains things nicely I guess you would of read it by now, so here is the deal.
There are several aspects that influence the hub score, some may argue this but this is from my own experience.
You said that some have more views but lower hub score, that is mostly due to two simple facts:
a) too much competition in that topic and your hub cannot be compared as quality hub, no matter the views
b) not an interesting topic and your hub simply can't get a higher view until the topic in general get's noticed by public
All in all you can get the score higher by writing insightful hubs that will make people want to comment, that is a good way of seeing if your hub is any good, more comments, more food for thought, and of course bigger score. Linking to your hub is also a way to get your rating up, and I mean not just linking from other hubs, but from other sites, ezines and blogs, those backlinks will help your score for another reason. HubPages (again, this is according to my experience) will give you a greater score for visitors that come from other sites than for the ones that come from HubPages, which is mostly 90% of our traffic at first.
Hope this helps as it is not fact but something I noticed along the way!