Why are fighting Retainers bringing back fish?

[Saseal]

My fighter-based retainers (well, atleast one of them) often brought back furniture the most (I had a million maps of Eorzea for some reason).
I'm fairly sure they're just going and either:

A.) Looting some FC's house (in regards to the furniture)
B.) Bullying a fishing retainer out of their fish
C.) Didn't feel like working so they set up a pole and took a nap
D.) Went to an aquarium and now have express interest in all fish
E.) There's a high % of fish items in the game and therefore the roll of the dice has a higher chance of landing on one.
F.) The devs have a sick sense of humor

[Celaine]

I could understand if it was something that dropped from a monster or a dungeon, but why is my i90 THM suddenly unequipping all his gear and switching to FSH?
I understand wanting to give us "trash" items but can we atleast make this make sense?
Only FSH retainers should be bringing back fish.

I thought it was obvious? Clearly our retainers are lounging on the beach up until two minutes before they're due back. They have an OH CRAP moment, grab the first thing they see... usually seaweed or a fish, and cheerfully bring it to you!