Because Google is big enough to make a big impact on the global conversation. By funding only groups supportive of them they can provide the illusion of unified support.
Google plays a huge role in our lives, but it is also a corporation that has a duty to its shareholders. The EU's decision has an impact on their profits that has the potential to affect their future revenue opportunities. I'd see an issue if Google was intentionally burying information from this group, but choosing not to fund them seems like a perfectly rational, fair thing to do.