Sure, we can choose how we react emotionally to events, to the extent that we have that self-control. But that doesn't mean all such reactions are equally valid, regardless of the situation. The circumstances can call for one reaction rather than another. If a natural disaster kills millions of babies, and someone's overjoyed about that fact, that person is probably mentally disordered. Emotions are ways of dealing with facts, so they can be justified or not, depending on the circumstances. The fact that we can rein in our emotions, or train ourselves to react in unconventional ways doesn't imply that emotions are never objectively justified. Alienation from nature is justified by philosophical naturalism. But that doesn't mean we have no responsibility as autonomous beings, and should blame nature for everything that happens to us. That's just a red herring you've added.