I could be off base, but the growing consensus is the motivation behind the terribad wipe your Epic Destiny TR proposed changes was that players weren't playing the stuff at the cap enough because TR was available. I personally think this is an incorrect perception.
If Turbine were to ask me why I don't play stuff at the cap and TR I would reply:
1. I prefer the heroic stuff for several reasons among these are, in many quests the difficulty scaling is out of whack for my current level of skill, equipment etc. that is to say, Epic Normal is a boring cake walk, Epic Elite is basically impossible or so time consuming that I just don't want to do it, and more often than not Epic Hard misses the mark in either direction.
2. I hate Drow Priestesses, the ability to drain something that I can't even see or in some instances even get to is a pain. Couple that with chain comet fall, command, self healing etc.
3. Leveling off destinies is a pain. Being compelled to level off destinies because you want to TR from a caster to melee for a change of pace is annoying.
4. My expectation that the grind for the "good gear" in the current crop of Epic level quests will quickly be supplanted by the forthcoming new quests seem pointless.
5. I like to play DC based casters, which you basically can't in 20+ content.
6. My expectation that Past Life Feats are a safer investment, kinda like how leveling up Epic Destinies was until the recent announcement.
7. Fatigue. Quite frankly by the time I've run up 4.3 million I'm mostly if not entirely burned out on that play style. Which is why I like to TR into an entirely different one.
If you wanted me to spend more time at the cap, I would suggest in order:
1. Reduce the stupidity of the grind that is 18-20. Quest experience in this level should be at least double what it is now.
2. Make DC based casting relevant in such content.
Very little of my decision to TR has anything to do with Epic Destinies, Epic Levels, or Epic Gear. Most of my decision has to do with preferring heroic to Epic Content, the 18-20 stupid grind, and the fact that even with multiple caster past lives I still can't seem to make DC casting work in Epic Content.