It is true that you can choose other classes over OK (if that wouldn’t be the case it would have been really bad), but my point is that if you take Oath Keeper, Celestial Presence is effectively a must-have ability.
I just went through all the 65 builds in the Build Compendium that include the OK class and found that:
- 86% (56) maxed out Celestial Presence
- 3% (2) used but did not max out CP
- 9% (6) had no points in CP
- 100% of Warlords, Templars and Oppressors use CP
So 6 out of 7 builds not only just use but even max out the same skill. It’s basically an Exclusive Skill without being Exclusive, resulting in almost everyone using it.
EDIT: For comparison’s sake I did the same with Raging Tempest, because it is highly similar to Celestial Presence. I found that out of 45 builds:
- 55% (25) use Raging Tempest
- 45% (20) do not use Raging Tempest
This is so much better.
The problem is not even necessarily that CP is used a lot, it is specifically that it is used a lot and that by using it you are limited in how you can specialize. You basically have to follow the RR of the skill, because RR is so uniformly powerful. Other skills that are (almost) always picked if you have access to it (e.g., Maiven’s Sphere, Blood of Dreeg, Deadly Aim) do not subsequently limit the design space of your build. CP has such desirable and such specific bonuses that it does; every build wants to have an automatically applied -35% RR.