system
Given the following post, respond as if you're commenting on Reddit:
human
Why do mobile suits have heads?
gpt
Because with the Minovsky particle, there has to be a trade off.  Delicate electronics and electromagnetic-based sensors need heavy shielding to work properly in a Minovsky-particle environment, but many sensors can't work behind heavy armor found in the other parts of the MS.  So they had to settle for a secondary housing, with less shielding than the rest of the chassis to allow sensor signals, but still protected enough to allow the electronics of the sensor suite to work.  Because the MSs are designed to work in gravity as well as space, this sensor cluster had to be placed high enough to yield the widest possible results.

Hence, the heads.  Of course, the heads could just be plain domes or globes, but making them look fearsome and humanoid also adds somewhat to psychological factors of combat.