Since raid timer bypass is so popular, you can't balance guaranteed loot in a specific time frame for raids. It might take me 4 months to get what I want, but each passing month can be harder to get a group together when using a bypass could get players guaranteed raid loot in half the time. This leads to raids dying out faster than they should making it tougher to get a group together. After awhile you just want to run normal for completion when it can be tough to get a group to do higher difficulties.