If it was all about QoL, you'd see Demonologists take it. They don't. People wouldn't play BM whos pets make up more of a Hunter's damage than a Demonologist, and yet they play it, principally because it sims out best. All it's about is damage, nothing else.
Now I agree encounter issues with pets need to be taken much more seriously than they are at present, but that doesn't change the fact that even with all things being equal, people will still demand "their favourite" be marginally better for whatever reason: The post earlier about Sac being more susceptible to errors in play and movement for example, presumably in order to vindicate their choice to any doubters. I believe it's for that reason that they tuned Sac to play that bit better because by and large, encounter issues with pets once you know them, can generally be managed through and worked around.
I think at this point though, that the improved QoL from Sac that people are demanding and apparently so love takes enough pressure off the player that there is less loss, especially combined with KJC, than needs to be compensated for by better performance and so they're fully justified in reining it back a bit and letting pets do that bit more to make up for the known issues with AI. Right now, as others have said, there is no downside to Sac for Aff and Destro: You get more damage and better QoL - I don't think that's fair on players who want to use their pets, and believe me, they do exist.
Personally, I would actually like to see Service perform that bit better than the flat damage options, there's just no good reason why a DPS cooldown which requires good use of timing should perform worse than something that requires no further management (Sup), or straight up less work altogether (Sac).