The grenade had a short range, limited power, and a long reaction time. In this battle, where the leading roles should have been played by aerial bombs, artillery shells, and anti-aircraft guns, there was no place for hand grenades.
The key issue was that the small monsters were constantly moving. By the time a grenade was thrown, the monster would have already run off.
Attempting to predict their movements and toss a grenade right beneath their bellies was easier said than done, and even more difficult to achieve in practice.
Thus, while a method to counter the small monsters had been found, the execution was too demanding, rendering the effect almost nil.
The anti-aircraft gun had sufficient power, but the small monsters moved too quickly and were too small. Moreover, most of them were in the crowd now, and no matter how powerful the anti-aircraft or machine guns were, one dared not fire into the crowd.
