Primary attack on the pick will hit the ground beneath your feet.
Alt-attack with an axe will, too.

Primary attack with any hammer other than the building hammer (which has no attack) will perform an AoE attack on the ground in front of you.

I'm not saying you're wrong, just pointing out that there are workarounds.

Only being able to hit below your waist with specific weapons or during certain times during an animation is the problem. I need to be able to hit things below me on rough terrain whenever I swing a weapon. Workarounds are not what I am looking for. I want them to improve the mechanics. That won't happen unless people point out the flaws.