Reason why Howitzers are not popular:
-Commander wise they mostly don´t fit on the meta
-They get heavyily countered by offmap
-Performance was greatly killed during some patch
Axis use to fire 12 salvos, it got halved. Soviet one used to fire 8 (?) and also got halved. I think cooldown is 90s for both.
B4 used to have a 2min cooldown, which was later moved to 60s
On this point, i guess that the overperforming was a thing for how easy they were to get killed. They reduce the performing but killing them still remains a 2 click action.
Reducing mp for howitzers MAY make them less cost effective to deal with them with pure offmap + recon run.
That they fire less rounds doesn't really matter though. Peter Qumsieh said that the first shots are the ones that count anyway, that's why they halved the amount of shots.