Let's be honest here though, the reason for that is because they didn't want to have SP Knight Enchanter and MP AW using melee warrior weapons. This is why SB is what it is.
SB is was built to be a spammable auto-attack substitute, the "cost" of it was never meant to be mana but the skills slot.
If that was meant to be (which I'm not agreeing with), then why was Spirit Blade so powerful from the get go? The devs couldn't have been oblivious to that. I disagree with your assertion about SB originally being intended as a filler skill. Especially when taking into account how effective staff attacks are in conjunction with Gathering Storm and other skill usage, it makes it seem like Spirit Blade doesn't have any business being on my skill bar. Why? Because running without it leads to better results in all but perhaps a couple of specific situations. And I'm pretty sure no other class has any skill that could be considered filler like Spirit Blade is currently, which makes SB seem even more like a bastard skill.
@Shadohz: I haven't played all the classes, and that's a surprise somehow? Not all classes appeal to everyone. It's common sense that not everyone is going to play every character. Also, I didn't make a suggestion for change that would have a direct impact on the abilities of more than one class, so why are you saying that I made a suggestion for change that would (well, it most certainly seems like you did anyways. There's not much point in making the statement you did unless that's what you were trying to say)? Also, just because people clamor for a change doesn't mean that I agree with it. As I said before, I don't care that the AW has greater survivability than most other classes
And there's a reason why I say wait until patch 8 before making any drastic changes; The reason the AW stands out is because of how crappy guard is compared to barriers in terms of durability (which there should be a difference since barriers have a duration) in DAMP. In single player, guard can become very, very durable (so much so that I stopped caring about having barriers handy, lol). But in DAMP we can't reach the high armor values (and resistance values without massive promotions) that give guard its durability, thus making barriers obviously much better for survivability in DAMP. The problem lies more with the incongruence between SP and MP damage mitigation systems.