The problem aren't the Steady/Obey stances themselves, but the fact that once you decide to use one of the pet's CDs (which they don't use under Obey/Steady), the stance will switch to default and you can say goodbye to the rest of your CDs as well.

Typical example for me playing SCH.

I keep Selene under Steady all the time, so it won't use CDs on its own. I decide to use Fey Glow, it happens. However, Selene will also immediately use Silent Dusk right after Fey Glow, almost always wasting the CD. The only way to prevent this is to put Selene (or any other pet) back to Steady/Obey just before the CD's cast bar finishes (Fey Glow has no cast bar) and even this is a gamble. 50% of the time you do this, the CD's effect won't go off but you still wasted the CD.