I personally cared for the characters myself.
True they were sometimes bit too edgy,
but honestly they felt often more real, than people in many other Tv-shows.
I also really liked the Adama-Roslin relationship. It showed nicely the more caring and tender side of Adama( yes, he had that side).
NuBSG was not a perfect show, but it is a damn good one.
Lots of good drama, interesting characters, plot twists you don't see coming..and some cool action,too.
Plus the cast was very talented and so was the writing
You need good character interactions when you don't have the "planet of the week" format that Star Trek relies on so heavily. You see the Enterprise's crew is not all that interesting from a dramatic standpoint, most of the drama comes from outside the Enterprise, not from within, in BSG you don't have a lot of interesting things outside the Fleet and the Galactica, therefore you have to make the crew interesting, you got to generate conflicts from within. Star Trek doesn't have a lot of internal conflicts, it is usually the outsider that causes trouble.