Is there something from stopping them?
They could ya know... just tip it over and then break it
Game wise, it would be unfair.Lore wise, so the survivors have more hope?
Because if killers could throw down pallets, they would just use brutal strenght all the time and destroy every single pallet in the map, leaving the survivors with nothing but windows.
Perhaps there could be a killer that would throw down pallets and block windows for some time, so survivors couldn't use them for a while, if you get what i mean.
pallets are god and cant be touched by those unholy beings
You have to keep in mind, this game is not only a video game, but in universe the trials are also essentially a "game" designed for the survivors to have a chance.
So whenever the out of universe reason is "game balance" the in universe reason is "because the Entity wants a fair fight".
It's for the same reason that survivors can have giant meathooks driven through their bodies multiple times, only to be in tip top shape after a friend gives them a back rub.
Because they're too scared of them to touch them, obviously.
On a serious note though, it's simply because they have to follow the Entity's rules, and the Entity gave survivors pallets as their main way of defense.
i love how hillbilly and leatherface can both use their chainsaw to break dropped pallets but they get stunned if they try to break it while it's standing
Sure mate, go destroy all pallets while we finish the gens :D
Lore wise, both the survivors and killers are trapped in a dream like state. Have you ever had one of those dreams where you seem limited in your actions, like you can't run away from a pursuer? It's sort of like that. They are like puppets in The Entity's game, with a limited amount of agency. It's the same reason why survivors can't just hop the fence and escape.