Horhay, as someone who works for an animal-related charity, allow me to take umbrage. 
First, I’ll back up and say that I’ve worked for three different nonprofits in addition to volunteering for a lot more. One of the other nonprofits I worked for was a social-justice-for-the-working-poor nonprofit that tried to coordinate efforts of different grassroots organizations in the Western hemisphere. One of the other nonprofits was a substance abuse prevention education office that gave workshops for religious leaders, teachers, and other community figures in addition to providing one-on-one classes for kids who’d been arrested for substance abuse.
I give this background to dispel a common myth: people who work for animal-related nonprofits aren’t blind to the problems that face human beings.
Given that, everyone does their good work in a different way (and I’m sure, Horhay, that you’re doing plenty of good work yourself). Those of us who work in animal-related fields tend to believe that humans have a duty to treat animals with respect and kindness.
Lots of folks in the field have quasireligious reasons for doing the work as well: they feel that humans as a species owe something special to dogs and cats as species, since we domesticated them. They feel that God, in giving us dominion over the world, requires us to take care of other animals in the world. There are lots of different motives for folks who do the work.
If you have time, though, go by a metropolitan shelter and talk to them about some of their cruelty cases. Take a look at their evidence photos of horses whose every vertebrae is showing in sharp relief. Look at the pictures of dogs with exposed broken bones, the result of “discipline” from their owners, or with the insides of their mouths riddled with bite scars, the result of staged dogfights.
My first week on the job, I got exposure to a lot of this kind of stuff. It opened my eyes.
Again, those of us in this field aren’t in any way blind to the problems that face humans. But we know we can’t solve every problem, and we’ve chosen to focus on one specific area where we know we can make a difference.
Our donors, presumably, have made the same choice.
Daniel