I'm not opposed to the relics being made as comparatively useful as those of the DPS relics. I believe that they are already there and have been for a while. The only place where they're *not* is in the duration on the use relic.
It's important to keep in mind that even the DPS relics aren't purely focused on DPS: they still have some amount of Endurance on them. As such, I think that it's appropriate that the tank relics have some degree of threat generation improvement on them. Hell, without some amount of tangential DPS stats attached to mitigation stats, I doubt most tanks would have *any* threat generation stats (I'm weird though, I stack Willpower way heavier than most Shadows do, though I do it at the cost of Endurance; it makes my threat beastly and I'm still just as hard to kill as anyone else around), and I think that it behooves the developers to make sure that that tangential stats are present.
Sure, it would be great if they dropped some of the passive Endurance for a *useful* tank stat instead of Power; I would use those in a heartbeat if they were added because I'm a mitigation stacking crazy person but, from an overall design standpoint, I don't think it's the best way to do it. DPS classes already ride hard on the heals of some tank's nominal threat generation; if everything tank related is hyperspecialized around mitigation stats, we'll get to the point where taunt spamming is the *only* way to generate enough threat to keep up with DPS.
It's not so much a stand based on "what would be best for me as a tank personally" (I'll readily admit that the relics you came up with would be more "optimal" than what we've currently got) and more of a stand on principle that, even in a game where specialization is key, no one should be able to hyperspecialize to so much that they're largely incapable of providing some progressively increasing degree of personal survivability or damage dealing as they progress through tiers of content.
I do the same with the augments on my powertech, i got to 53.5 shield and 56 absorbs thru gear and just loaded all reflex augments. Figured the xtra endurance and a lil more dps couldnt hurt. sitting at 1934 aim.. as a tank lol just under 28khp