Since we don't know how and when the devs will make changes to the game to make grouping more desirable, I suggest we as players do a few things to get more people grouping.
> Post some of your LFM's as normal or hard difficulty. There are some players who are not interested in reaper, and the only way you can get them to join is by posting a quest at a difficulty at which they want to run it.
> Be willing to join quests that are posted at normal or hard, and don't pressure the group leader to switch to reaper once you have joined.
> Be willing to take the quest at a slower pace if that is what the leader wants. For some of us, the goal is not XP/min, but enjoying each quest for what it is and socializing with the other party members.