They have class C shares, which do not have any voting rights. Shareholders without voting rights have absolutely no power to influence policy.
> If they lose more employees it can be argued that they're ignoring their fiduciary duty to the shareholders by tarnishing the brand of Google which makes hiring more difficult which leads to less profits.
You're making a lot of jumps of logic here so I'll split things up:
> If they lose more employees
They're not bleeding employees so quickly that it will cause a problem, the overwhelming majority of Googlers will not leave over this. There's just a few of them, enough to make headlines but not enough to cause any real issue.
> tarnishing the brand of Google
They'd have to tarnish it a lot to get people to stop wanting to work for Google. Even with the latest headlines and controversies, it's still one of the best paying companies out there with awesome benefits, interesting work, and prestigious status. Even employees who are uncomfortable with some of the choices the company is making will think twice before giving all that up.
> which leads to less profits
In the long run this might be true. I'll use the counter-example of Microsoft though: they were the demon for decades and are still one of the most valuable companies in the world. If a tarnished brand for employees guaranteed less profits, they would have died a long time ago.