That's what it comes down to, isn't it? Pets are more work than not having a pet, and they often don't deal their maximum potential DPS. The thing is, I bet you that Warlocks are balanced with that as part of the calculation. This means that if pet vs no-pet are equal on a simmed Patchwerk fight, then no-pet is ahead on every real fight where you're able to bypass all those little inefficiencies that pets have. That's what the Devs are probably so set to try and deal with.
Ideally, GoSac is a tradeoff. What you gain is the increased ease and efficiency of not having to manage a pet. Only right now, what you give up for that is nothing. There's absolutely no down side to GoSac. I think in part this is the Dev's own fault, though it's because they listened to the community.
We begged for the freedom to to choose between demon pets instead of being chained to a specific one by our spec. The Devs did their best to deliver, and they sort of did. Minor DPS differences aside you can freely use different demons, because minor DPS differences aside it doesn't matter. In a group situation they don't have any significant utility or buffs. Even the Imp's health buff is getting moved off them. They took out the unique spec interactions, like Imps procing instant Soul Fires or Felhunters hitting harder on targets with DoTs on them. Only now there's no interaction at all. My BM Hunter alt has a complex dance of buffing and being buffed by his pet, while my Warlock has none of that. The demon is, most of the time, a fire and forget DoT. The only effect of a different demon is to change what my Command Demon button does.
In short, the demon pets barely matter now, so many Warlocks resents the extra hassle of having to use one. When the option to ditch the annoying pet for equal or better DPS is dangled under ours noses, it's a very tempting offer. I'd love to see the Devs fix this by making the pets matter again, but that's not a fast or easy change. Instead they're doing the quick and dirty fix of slashing the DPS so that GoSac is lower on a simmed Patchwerk fight and roughly even on an actual play one. Which is very quick and very dirty, but mostly accomplishes their goal of not having GoSac be better in every way.