Sorry I was rude, I just know how it is, to stand in the rain and try to get someone do something painless for the greater good and have them turn away for whatever reason.

On another point, here's a case study of lesser proportions.

Suppose you generally want to fight social injustice, save Our Planet, uphold peace, defend women's rights etc. (as many do when they just begin deciding what to do with themselves). A friend subscribes you to a NGO for nature conservation, and you think it might be a good place to start, since you don't have much money to donate, you are vaguely afraid of catching a disease from poor people, and it's safer to explain to your parents anyway. (I'm not saying it is morally right, I'm saying it is common.)

You, like Paris, are presented with a choice. You can give your all (money, career, way of living) to one out of three goals, each one (considered by many other people) noble in its own right, and be quietly damned for not picking any of the other.

Your criteria of choice are: Beauty, Harmony and Kinship (again, this is just empirical - I've seen many people start with these). Note that each of them gives you equally strong feeling of being in the right.

Beauty means you would protect flowers and birds and aesthetically pleasing things. It is easy to devise a way to target certain species if you know something about the threats to them. Let us say this is the species-oriented approach. Harmony means you would urge people to 'live green', educate masses about the value of the Earth, maybe rail against nuclear power plants and other clearly dangerous projects. This will be the people-oriented approach. Kinship means you would fight for abused animals (pets, victims of scientific experiments, circus animals, large mammals going extinct from poaching, etc.) This will be the problem-oriented approach (I know, lousy naming).

However, efficient nature conservation turns out to be quite different from your visions. Your priors turn out to be biases.

Because protecting single species (Beauty) almost always fallso short of the objective, since the major cause of species extinction (at least in terrestrial ecosystems) is habitat destruction. Curiously, many beginners find it easier to invest efforts into saving individual lives but not into ensuring there is a place for the organisms to live, propagate and disperse. A life (or often, one season of it) is something tangible; a possibility is not. (And it is statistically hard to fight against land developing companies and win more than a season's delay before the habitat in question is razed to the ground. Also, the danger to the activist is proportional to his impact. I should think it is so for human-oriented initiatives, too. It's one thing to raise funds for cancer treatment, it's another to investigate illegal trade in human organs.)

Because pursuing Harmony mostly gets you to discuss misconceptions about concervation (the deeper you dig the wilder they get), and protesting against power plants rarely succeeds at all. Not to mention that this way doesn't begin to cover the more common (and tawdry) threats to biodiversity.

Because Kinship is not about nature, it's about virtuousness and kindness.

In the end, you either shrug and say, 'I've tried' or specialize in some branch of ecology. Very few people start with science, but they are more likely to continue working. 'It is the good thing to do' is not a strong enough motivation for most. It's simply not efficient.