Easy solutions to annie's rise in popularity.
Code her ult to work like gragas' ult, that way people have time to react to her ultimate instead of having to deal with a instantaneous 100-0 possibility. Her ult provides far to much reliable utility AND damage. Code it like gragas' ult and i guarantee it will work.
If that is not enough, change tibbers into a linear skill shot that does a aoe knockback to whatever it comes into contact with it.
2 simple solutions for a simple problem