It's quite something when the welfare of animals is far more important than the welfare of humans. Why don't they protest about homeless people?
Now that's just a silly argument, and one that was thrown a me a few times when I was collecting money for an animal shelter. By that logic we should all agree on what 'the most important cause' is, and only give money to and support that one thing. In the real world people are moved by many different things and if they are going to make an effort to support a cause or to give money to a cause, then of course it should be a cause that most pulls their heartstrings. If someone else thinks something else is more important, then they should support that cause and do something about it themselves and not berate someone for supporting something different.
I will always support animal charities above human ones. Other people will do the opposite, for some it will be environmental concerns or whatever. No one should be condemned for supporting a cause (and I'm not talking about these protesters here - the means they are using probably should be condemned - but not the desire to protect animals), we should all be grateful to anyone who is prepared to put themselves out in terms of time, energy or money, to make a positive difference to anything and not criticise them because it doesn't happen to be the thing we would choose.