First of all, I have both an operative and a sorc healer. I mostly PvP with my sorc healer but I do some pvp with the operative too, so I have a pretty good idea about the pros and cons of each class. I love both of them equally - the only healing class I do not like at all is Merc healing - but I do think you are being a bit harsh on Sorcerers.
Operatives are the best healers in the game. A good operative healer will out heal any mercenary or sorcerer healer. Operatives also have the best crowd control and survivability between all three of the healers (cover, stealth, sap, and flashbang being big ones). They are also extremely mobile with most of their heals being instant. At 30% health they have an instant free spammable heal as well. Basically, their tool set for healing and staying alive is way better than a sorcerer's.
Operatives after patch 1.3 (it was 1.3, right?) are on par with sorcerers in terms of healing output. What makes them "best healers" sometimes is that they have much more survivability and crowd control than sorcs. Therefore they survive longer -> they heal more. They are not only good healers, they can also enter and exit combat whenever they want (provided their combat stealth is off cooldown, of course) as opposed to sorcs who have to -one way or another- finish the fight they got themselves into. They also have good crowd control and yes, if the target's health is below 30% their free instaheal continues to stay up.
But there is a reason for all those things.
Sorcerers are the second best healers in the game. This is because of their Static Barrier skill, or "bubble" as most people refer to it. It can be placed on anyone on your team, and when it breaks (if you have the Backlash talent) it stuns everyone around that person for 3 seconds. Also because sorcerers have a friendly pull which has great impact on the Huttball map (and is still very useful on other maps).
First of all, when we're talking about Sorc vs Op healing we must make clear that we're talking about Pure Healing builds, not hybrids and that your opponents and allies are of equal skill and gear.
It's understandable that without one of their most important heals (Revivification - aka the Aoe Heal) that some Sorc healers choose to give up in order to get the Backlash talent and therefore up their survivability, it's unfair to say that they are healing for less than what Operatives heal for. And the Aoe heal, especially in warzones like the Voidstar could make a Sorc outheal an equally skilled Operative healer.
Also unfair: The bubble does not count as healing when you look at the numbers at the end of the warzone.
Which brings me back to your previous statement about OP healing:
At 30% health they have an instant free spammable heal as well.
Yes they do. But on the either hand, Operatives have no way of preventing damage, like Sorcs do. That's their "bubble" (which counts in the final warzone numbers, unlike the Sorc bubble) because they have no way of shielding their opponent.
But I can guarantee you that the combination of Bubbling up an ally and pulling him to you, away from the 3 other people (aka Marauders) that are beating him down, can be much, much more effective than the Operative's instaheals, that could or could not crit, could or could not outheal the damage etc.
That being said, sorcerers have the lowest survivability of any A/C in the game, not just out of the healer A/Cs. You do not have a defensive cool down. Meaning, you have no skill on a long cool down that will reduce or prevent damage being done to you for a set amount of time. Your heals are all casted. You have no real worthwhile instant heal accept for Unnatural Preservation which you can only use on yourself and has a 30s cool down.
This is all true. Except maybe that the bubble is an instacast. Maybe it's not instaheal but it does prevent damage. And preventing damage is sometimes the best - and most cost-effective - way of healing.
So to sum up. If you want to be able to cast a lot of heals while moving, and beat most everyone in heals the majority of the time (and also have great crowd control and survivability), then operative is for you.
If you don't mind having lower survivability and being forced to cast all of your heals while standing in place, then sorcerer is for you.
The way you're saying it is like saying "if you want to have fun, roll an Operative. If you want to get roflstomped and feel useless, roll an Sorc".
And it's not that way at all...
Yes, Sorcs may need a bit more pampering than Operatives but they can make a significant difference in warzones if tanks guard them and understand that they are not punching bags that can take a lot of beating without going down.
Sorcerer can be fun if you enjoy this type of play style and embrace it. But you will never be able to heal like an operative as you are too restricted by having two, 3 second cast time heals. Your only instant heal is on a 30s cool down, meanwhile an operative can spam an instant heal costing no energy at 30% hp or less along with other instant heals. There really is no comparing the two. It comes down to what is more fun if you can't decide after reviewing facts like these alone.
Sorcs are fun to play if you realize something: kiting is of the essence. People will see you in a warzone. In fact, they will seek you out because they know you can go down easier than an Operative healer and try to get you out of the way as soon as possible.
But, unlike Operatives, Sorcerers are fast. You can Force Run, Electrocute, Bubble yourself, Throw your enemies away from you and pull an ally to you to help you burn down the dps that's hurting you. If people don't realize that they need to protect their healers, no Healing class is good enough to make it on its own.
Even the free Operative instaheal below 30% HP - that Hairyzac seems to love so much
- will not save you if 3 marauders are on you and you don't stun and kite them.
I would suggest you watch videos of people healing WZs as Sorcs and as Opeatives and see which play style suites you most.