The game is already doing the roll for you. When it randomly assigns the scroll to someone else, it's doing exactly the same thing that rolling does: you have the same chance to get the scroll.
if the player doesn't want the scroll, they can then put it up for roll and give you another chance.
How exactly is 5 people rolling a d100 more fair than the game randomly determining a player to give it to?
This is roughly the same as claiming that a player who gets raid loot must put it up for roll and beat everyone if he wants to keep it.
I, for one, will absolutely require any group I'm leading to simply accept the random determination of the recipient, who can then pass on it if they want. It's already randomly-distributed loot now. You have no right to a second chance.