In most content, it is not what you are describing, it is an unnecessary button click that more often than not bugs out/doesn't register when you push it. If I misclick Cleric Stance in 90% of this game's content, we are still nowhere close to wiping - I am just needlessly annoyed.
To extrapolate further, the recast timer on CS is a paltry 5 seconds - about 2.5 globals given our current GCDs on abilities. Unless you are using it while the group is already at low HP and struggling, there are precious few things outside of one-shots that will bring a group from full HP to 0 in the span of 2.5 globals. The one content where that might happen, Savage raiding, is full of encounters so scripted that a program can bleep at you what is going to happen next, giving you tons of windows to toggle the button without issue, and if something DOES go awry while you have it up odds are it's because someone bungled a mechanic and it's probably going to lead to a wipe anyway.
I'm not saying I dislike it because I find it difficult to use, I'm saying I dislike it because it doesn't add anything to the game whatsoever at this juncture. I feel like it was ORIGINALLY intended to be a risk/reward ability for healers while out in the open world doing content, but due to this game's glacial GCD and ridiculously scripted encounter designs it doesn't add any element of depth or skill to the job; it just adds another button to my already-crowded hotbar. Removing it won't make healers these OP gods that will smash through all content solo on day 1 with ease...at best you'll be able to get 1 extra heal off that you wouldn't have before. Currently, you're able to finish out the timer just from applying your three healer dots, and pretty much EVERYONE has the space to do that in all this game's content...might as well just remove the unnecessary button press in-between.
To summarize, HERE is how Cleric Stance would actually be high-risk/high-reward:
-it cancels all HoTs on everyone in your party
-it Dissipates the fairy
-it lasts for 10 seconds and is also on the GCD (meaning you can't just click it off and Lustrate/Tetra/Dignity before activating it again within the same GCD)
-maybe remove Stoneskin and Adlo too, though that's probably overkill haha
As long as you can basically stack HoTs and have the fairy unaffected by it, there is not any real "risk" at all to Cleric Stance.