That happens
a lot. One thing to notice is that the average score a particular user gives the artists is
tracked on their profile page. That has been a deciding factor for me. I won't support those who are unkind to others. That doesn't mean I'll sink them with a poor score. I just won't give those users a
high-5.
I'm fair-minded so my median score is
3.25 / 5.
You're median score is even better than mine. Yours tracks at
3.75 / 5.
The entries in the top five tend to give a lot of
2's. I think that's kinda tacky!
In the end, none of it really matters as much as what Henson and Threadless think makes for a profitable design that best represents their brand.
Personally, many of my favorites didn't make it to the top page. Some did, but there are a lot of fantastic low-rated entries.