This discussion reminds me of the time my speedometer broke. Suddenly I'm being told that I can't go over 80, but also don't want to go too slowly or I'll cause traffic problems (and just take forever to get there), while having no idea how fast I'm going. On a busy road I can at least go the same speed as everyone else and just assume they're doing the right thing, but on a quieter road or a highway I'm blind to how I'm doing.

This is a DPS focused game, like it or not. Killing things is the primary way to interact with the world. Killing things faster makes everything easier on everyone, and going too slowly tends to lead to problems (as a trial roulette Lakshmi group learned yesterday). For hard content, you need to kill stuff within a certain time or you fail.

... and yet, the plan is to conceal how well you're doing at that? I normally heal, but I have a 70 RDM. I know I'm on top of rezzing and mana shifts and such, but is my DPS where its supposed to be? I have no idea. That's kind of a problem when I'm a liability to my team if it turns out I have room for improvement. Would changing melds to different things make it better? Luckily there's other people to do analysis and parses and let me know, because the game doesn't give me a terribly effective way to figure it out on my own. By default I can't even rely on a comparison to someone else (like I can in my car) because there's no way to tell how much of the health bar going down is me and how much is them.

Like any tool, it can be used badly. But it's such a fundamental piece of information that they're trying to conceal (and failing if you have a PC player do it for you) that it mostly serves as a barrier to people who aren't advanced enough to know where to look. I can't attempt to fix the problem if I can't tell where the problem is.