How do you expect to keep players when they grind to raise their light level and you cap the light level at 1815 for difficult content. If the average player can't raise their light level to give them a chance to complete the harder content. Then what is their incentive to play your game? If you are going to cater to the elite players by making a very difficult and impossible activity to complete, then you are only going to have a very small pool of players after awhile, who will get bored after completing these activities and leave to find other stimulating content.