This is like that thing Eliezer said, where if you start arguing that we should reject consequentialism because it would have bad consequences you need to step back and think for a second.On the surface of it it seems quite clever. People who argue against consequentialism do point out the bad consequences. Then the defender of consequentialism can always reply. Well you just didn't do consequentialism well enough. You didn't put this particular consequence into you calculation. If you had done that then consequentialism would give you the right answer.
The trouble with this is it takes the knowledge of hindsight and assumes it is always available as foresight. That is one of the main problems of consequentialism. We don't know all the consequences. We can foresee some of them. Even with those we tend to overestimate how accurate our predictions are. But there are a ton of consequences that we just don't foresee at all. Sometimes we can see them after they have impacted us. Often we don't even notice them then.
We tend to be much more likely to notice physical consequences. Not that we get even half of those right but we are horrible with spiritual, emotional, or philosophical consequences. How does this impact the way we view the human person? What will this do to my conscience? If everyone lives this way what will it do to human relationships or society as a whole? These questions actually get you into the whole idea of morality. Often consequentialism misses them entirely. That causes some to say consequentialism has nothing to do with morality. That is not quite true. Still it does seem hard wired to prefer lesser goods to greater goods. That is because lesser goods tend to be more immediate and more physical and therefore are much less likely to be missed.
Take an example of divorce. If someone is considering divorce then the positive consequence is going to seem huge. They can rid themselves of an obligation which they have come to resent. What about the negative consequences? Those are less immediate and less predictable. You break the most solemn promise you have made in your life. So what? What does that say about who you are? That is pretty hard to quantify. What does it do to marriage as an institution? Every broken marriage vow cheapens future marriage vows. Will it cause friends and family to have a harder time taking their marriage vows seriously? Hard to know. What about your relationship with God? How will that be impacted by your divorce? Not sure but it can't be good.
So you end up with skewing the process in favor of the most petty and pathetic considerations. What is more it assumes you are competent to weigh all the consequences. But we know people can get ideas in their heads that all their problems will go away if they could only get a divorce. Morality is supposed to protect us from our own bad mindsets. Consequentialism does not do that at all. It does not do any of the things morality should do. It does not value timeless principles. It is not oriented towards building inner virtue. It does not make you moral decisions more consistent.
In fact, what consequentialism does most often is make bad moral reasoning seem OK. It puts us in the center. What we see as important at this moment is important. What we don't see at all does not matter at all. But you feel like you have done some moral reasoning. Really what you have done is rationalized bad behavior. We trust our reason more than we should. Our minds can give us a very skewed picture. We should trust reason in general but look to tradition to guide our thinking.
Consequentialism also has a self-referential problem. It talks about which course of action has better consequences. But when you define morality you can't use words like "better." That is one of the concepts you are trying to define. So often consequentialism will become sentimentalism at the final stage of analysis. What is better is what seems emotionally better. So it is very changeable based on the picture you have in your mind.
We accept torture after 911 not because the moral reality has changed. Just because out sentimental picture has changed. We imagine the torture victim as a terrorist and the torturer as someone trying to prevent another 911 or worse. So we don't see one human person treating another human person in an inhuman way. We see a hero and a demon. But then we try and tell the Syrian government that they should not torture. In our minds it is a very different picture but we have taken our minds out of the picture. Our analysis of the consequences does not matter. It is the thinking of the Syrian leadership that matters. We have nothing to say.