I'll give some thoughts. I didn't mind debt so much in CoH in later games, as it was small enough it was quickly taken care of. But I felt the amount you could accumulate was far to much; if you got in a horrible team, niceties could either go out the window to save yourself from slowing your leveling far to much, OR you'd end up with half a level of debt to deal with. Bad players had things especially frutrating in that they'd level up super slow, and while you'd think more time = learning more thats not always the case. Sometimes there isn't anything new to learn at a level range and debt keeps you there, and bad players generally don't tend to learn very well(either due to foo strat dependency or just not willing to learn). But debt didn't really mean anything at level 50; who cares if I lost some influence later, cared even less when influence became so devalued that I was more worried about things which debt could never effect: IO recipe drops and the massive profits I made from them.
I also dispise however losing max health/energy after dying to though, aka guild wars. It was impossible to avoid dying excessively if you fell below like 40% death penalty as your lowered max health made it easier for you to die, and enemy npc's would auto-target the player with the most death penalty automatically in a team, causing that player to become a perpetual punching bag.
To me, debt wasn't bad but I feel it had to be small. coH the debt per death was about right in missions later(about 1/5th an experience bar, or 2% of experience needed to level), but I felt the max debt (50% of experience needed to level) was to high. I also wouldn't want to have health loss from dying in an mmorpg where we can fight mobs in city zones.