Like most ultra-left-wing radical groups, they love the idea of Saving All The Animals(TM), as long as it's someone else that has to do the work.
We used to have some liberal asshat who worked in our office, and she would constantly go around showing pictures of animals at the local shelter who needed foster homes. One day I asked her how many dogs she was fostering at home and she said, in a perfect sorority girl tone of voice "oh, I can't foster. I don't have time to take care of them."
Liberals LOVE the *idea* of people making sacrifices for the benefit of others, as long as it is the OTHERS who are making the sacrifices.