It's a far more likely explanation that it's just a loophole Concerned Ape has simply let slide because fixing the loophole is more trouble than it's worth.

Likewise, consider what else would have to be addressed if you banned storing hay in chests Coding in a ban on stuffing hay in the chests would be an extremely tricky thing to do, not only because it would be the only such item in the game, but especially if it's also meant to be permissible to just buy hay from Marnie and stuff it in a chest if you have no silo or ran out. (In case you had a storm the last days of Fall/first days of Spring, or want to let the grass spread a little before letting the animals have at it.) 8 animals is 2 basic barns'/coops' worth. It also follows that you are meant to hve a certain ratio of silo to animal, since if you were meant to have infinite silo capacity with just one silo, why wouldn't Concerned Ape set the capacity to 9999 or 2,147,483,647? 240 is enough for 8 animals to get through the Winter with change to spare. Just think it through rationally It's fairly clear you are meant to have silos to be able to collect hay, as that's programed in, and there would be no purpose in a silo otherwise.

Click to expand.No need to get too defensive, there are plenty of exploits people choose to use in single-player games without hurting anyone, but they still are exploits.

Stardew valley silo recipe