When I read Chris's dev blog post about removing XP for trash monsters, I was dubious.
I then did find it annoying that they didn't give XP at first, as I was learning the game.
However, now I know that I have to kill bosses anyway for items and fun, it's not a big deal. In fact, I think Chris was right to remove XP from the trash mobs, else you'd level super fast and outlevel all the regions you walked to really quickly.
That said, Civ Level 1 is the hardest. Once you get to 2 it's much easier to kill (level 1 mini)bosses.