What a sad situation, Turbine this is your chance to fix it by making more money.
Since everyone is telling you that they are being incentivized to not be VIP, to not have epic tomes of learning, to not use XP pots, etc... Here is what you can do, if you are at all smart, to incentivize everyone again.
1. XP pots - add a % increase to commendations as part of the pots. Or you can offer commendation booster pots but I think in the end you'd make more money upgrading the XP pots and people would hate you less. People who want XP for heroic buy XP pots for XP, people leveling 20-28 buy XP pots for faster leveling to cap AND faster accumulation of commendations. Face it, you'd catch a lot more honey this way. Some people hate on you and will not buy those hearts while feeling forced to because of the stupid 4200 number. But add commendation boost in those pots and BAM, they'll buy pots instead.
2. Epic Otto's - despite what people say, someone who would buy this would not necessarily spring for an epic heart as well. Add a certain amount of commendations that come with the XP it provides. Impatient people might still buy an epic heart 2 out of 3 times or 1 out of 3 times, everyone else will at least buy your otto box. What you have now is the only people buying Otto are those already ready to buy hearts as well. You need to attract more people than that as those people will be done ASAP with all these pay2circumventplaying and when done with all the PLs, they will stop buying or playing.
3. VIP - nice that you are offering ONE free heart in December. It's one time. Every other time being VIP makes it so I'm more likely to grind at 28 for more commendations. BOO. Do the same as XP pots, commendation booster included. Don't incentivize people to CANCEL VIP, seriously what nonsense.
4. Epic tomes - we bought the legendary packs and such and now you are punishing everyone who used an epic tome on their character. Buyer's remorse is huge. Add commendation booster to the epic tomes.
ALL THESE CHANGES SHOULD RETROACTIVELY APPLY TO EXISTING ITEMS!
I cannot stress that enough, you have left a bitter taste every time you have changed items. Make it exchange-able with an NPC if you do not know how to re-code a database entry, *shakes head and sighs*. I'm not going to go into the sad state of your coding if you cannot do retroactive item changes.
Incentivizing purchase of one item does not work if you are deincentivizing purchase of 4 different categories by it. And Otto is more expensive than a heart last I looked.
And as a personal note, stop being so attached to Shadowfail. I get that you want us to run it more hence the higher level of commendations there, but you cannot force people to run unpleasant and painful content over and over... eventually we say to hell with you and DDO. Don't be so short-sighted, okay?
Get to work.