In which case, if you make your "principled" stance and bite Google's hand enough that Google drops the funding... great, you made headlines for a day, but it didn't really accomplish anything and have made the situation worse for everyone by making WebKit the only rendering engine left standing. Great job for principles.
In this case, I get it that they have Principles. It's just that those Principles will kill them and what they hope to accomplish by those Principles in the first place. In this situation, I would still have principles, but I wouldn't be so vocal about it until I could stand on my own two feet and withstand the loss of funding.
Imagine working for a boss and you find out that he is cheating customers for millions of dollars. Say you objected to your boss, or reported him/her to the police. Would that be ironic because you might lose your job?