#yeah i'm aware he used it at least once to pull madara's leg

[badly-drawn-pigeon]

What if Hashirama's theatrical depression fits are actually a mechanism that he learned in order to be able to express his sadness at all? Like, being down in a "serious" way could give him a beating from Butsuma because "it's shameful for a ninja to cry" and this kind of BS. So Hashi rather than repress these feelings began to crank up their expression to 300% and make an absolute show of himself every time he felt bad. This way, Butsuma could now say "my son is f*cking stupid" but it didn't carry as much condemnation as "my son is weak".