Well I know more than just a challenge was wanted. It is a very plain concept to understand: Risk without reward is never taken. Especially in MMO's. The problem I have with the reward system in Reaper is it shoots three times, hits the target twice, and the third ricochets and hits your foot.
People wanted a non-trivial challenge, check
People wanted a boost to some meaningful reward, check with a boost to pulling named items
People wanted some system that only makes the grind in reaper easier, *pichnew!* This one is the bad one.
I mean I get the meaning here. It adds something to aim for. However the reaper mode was more about item 1, a meaningful challenge. They did go full banhammer on players power. However to balance that, add a earn creep to get marginal returns? That seemed like the poor decision to me. In the end, that is what they added, so that is what we get. How could it be worked on and improved is the next step.
Personally, the one thing making reaper a must run, loot. In ddo there are two long haul runs: exp and loot. Exp has plenty of ways to gain fast and hard. Loot on the other hand is a mess of systems with many different ways to boost the junkpile, but nothing really boosts the quality pile. This extra chance to get better named items is a big positive in reaper.
Unless, like flagging mechanics, it was removed before going live and I am totally off mark and reaper has nothing going for it except challenge?