I'm pretty sure grenades exploding mid-air repeatedly would be similarly inhumane. I did happen to say ENEMY SOLDIERS. Meaning intended use for them. It's as easy as not using a certain destructive weapon in favor of more tactical weapons if there is civilians around. All wars have collateral damage anyhow, the most you can do is to try to minimize it, a good way is to use certain weapons in certain situations. Such as ooohh, i figured it out, don't use the repeating flak cannon if there is any chance of a civilian getting killed (now that's an idea there that i already mentioned in this post).
I still like the apache mounted repeating flak cannon.
Used in the right situations it'd be a great diversionary and deadly weapon that would ruin enemy morale so they run for the hills (enemy troops will not want to stick around when crap is repeatedly exploding above their heads).