The problem is that they still get money from normal people who don't realize their real agenda. It's a bit like smoking way back in the day - people didn't know it was harmful*, the tobacco companies were pushing untrue messages, etc...
PETA, the organization is a lot like that. They push a specific variation on their message to the world(be ethical about the treatment of animals!) that is non-offensive to the majority of people. As a result, pet owners will donate money to them, thinking that PETA is a bit like the old NRA(which put the money towards safety education, safe firing ranges, and such) - that their money would go towards animal shelters, education, fighting animal abuse, etc... They don't realize that their money is used to fund overpaid executives and push radical agendas.
As such, we need to scream it to the rafters until enough people know to give to their local animal shelter over PETA and PETA goes bankrupt.
*Well, many did, but it wasn't advertised, there were a lot of truly ignorant people.