It's just a matter of what ideas popped into our heads, and how simple or difficult they'd be to implement. There were other ideas thrown out that were more generic, but in the end they'd be more difficult to code or were overpowered or some combination of the two.

As for polearms, yes, I'd agree we are short on them - we even brainstormed up a couple extra specifically for them toward the end. I would imagine the next go-round will see more polearm goodness and less sword/daggerocity. We'll see!