I still can't see a chicken ...... starving itself to death.... when there is food there just because it's not the flavor the bird wants. Ive seen them eat each others' poop, so they can't be THAT fussy when they are hungry!
STOP giving them the scratch grain, just stop for a few days, when there are no more treats, they will start eating what you put down for them. As some of the others have said, wetting it down a bit might make them like it a bit more as well but once they get hungry enough, they will eat it. I have found with mine, when there is an abundance of food, they get picky, but when the food is on the ground being stepped on / into the dirt for a day or two and I decide NOT to put their morning breakfast bowl out for them, yah sure they cry for a little bit, but sure enough by noon, all that food that formerly was being stepped on, has now been eaten. Then they get fresh food.
Basically, if you condition them that when they stand by their food dish and cry, they get fed, that's what they are going to do every time. Or just don't eat 'THIS" pellet and I'll get a different type.
It's tough love sometimes but it works. and really, is for their best interests.