You do realize you can't replace power with accuracy right? DPS trading heavily DRed surge for some accuracy (Your options are alacrity, surge or accuracy) is the best option for min/maxing but it won't make a huge difference either way.
For DPS, yes, Accuracy competes with Surge and Alacrity on enhancements. For tanks, on the other hand, it competes with Shield rating, which tanks should always taking over Accuracy. Of course, in the pursuit of arbitrarily desired Accuracy, some tanks will actually aug for Accuracy, which should never be done, mainly because said accuracy will improve your DPS less than you would get by taking power or your primary stat.
Of course, for DPS, Accuracy is actually a worthwhile stat, but that's not what I was referring to; I was specifically rebuking the comment that Tanks should ever have accuracy on their gear when they have no mechanical reason to do so.