I, for one, was sick to death of the dreaded Stack of Doom that Civ IV and earlier had. Civ V was a remarkable breath of fresh air. Square vs hex just isn't a big deal to me.
Civ V's combat is frustrating in a lot of ways, the unit-per-square system makes ranged strength overpowered and takes away all value from numerical superiority.
But I still hugely prefer it to the doomstack approach - wars actually involve doing something now.