That could've worked.
The former objection of yours again misses the point that they would lose simply by remaining on the defensive, though. Giving up their mining operation was akin to failure. Holding out for backup could have meant billions (trillions?) in lost revenue.
I never argued that they should give up the mining operation, only that they were better served by strong defense of it then attacking the Na'vi in an effort to "defend" the operation.
You're right--it's not an argument, is a presentation of evidence intended to demonstrate that the colonel believed he already had a strong enough defense, and felt he had the resources to attack the Na'vi. With a strong defense and no reason to anticipate total defeat in battle, Quaritch views such a mission as within his means without sacrificing any strategic foothold. His technology is superior and his destructive capability outclasses the Na'vi. Had the mission failed, he would still be able to retreat and resort to defensive strategy. The Tree of Souls was a target of opportunity. He most likely didn't need to hit it, but if he did and still had some of his gunships at the end, he would have gained a more advantageous tactical situation.
Infantry tactics and terrain 101; jungles are very bad places to act on the offensive because they completely blunt firepower advantages, play hell with supporting arms due to their short sightlines, and ruin unit cohesion. It was true in the Ashanti expedition for the Brits, it was true in the South Pacific in WW2, it was true in Vietnam. You can't kill what you can't see, and in jungle terrain you can be close enough to your enemies to smell them or hear them breathe and be unable to locate them. Quaritch basically throws away most or all of his advantages of superior firepower and technology by commiting to this course of action.
I agree with you that "crush the morale" missions are generally ineffective, but only in regards to humans. We have only tried morale crushing on humans, and thus it stretches logic to assume the Na'vi would have the same resilience to Shock and Awe that humans do. We live in a society where our lives are so complex that losing something like the Vatican would not be as crushing as losing the Tree of Souls would be to the Na'vi. The Na'vi organize their life around the Tree of Souls and their connection to Eywa. Part of the Na'vi lives in Eywa, in the Tree, and killing it would kill part of them. Destroying the Tree would fundamentally undo Na'vi civilization.
The colonel was ultimately trained to fight other humans, however, and given how readily he ignored the science team, we have no reason to believe (hell, I don't think we can take for granted even the science team knew the details) he really understood this of the Na'vi. He adopted a strategy that would dissipate his advantages regardless of the final effectiveness of his plan, but we don't actually know it would have been effective. The Na'vi are not presented as so completely inhuman that applying our pyschology to them stretches anything.
Given the title of this thread, all you should actually need to know about such things is that they didn't work on less-developed societies either. Destroying a civilization in this fashion is never truly effective. What Quaritch needed to do, and what the plan I propose would have brought him, would be to bring a large force of Na'vi to battle and defeat them in detail, giving concrete results instead of maybe winning his morale-crushing victory or maybe making every Na'vi on the planet turn up to kick his ass.
That was why I drew the comparison to Ulundi. The mere raid is not going to inflict significant casualities on the Na'vi as they're not organized enough to stand up and take significant casualities when surprised. They're just going to disappear. But if you present something that insults their honor, that they must take back no matter the cost, you can bring a significant portion of them to battle and have a good chance of killing them all because even they will reform for multiple attempts.
