Facebook doesn't get these things for free. Facebook is no more able to commit copyright infringement than you are.
There's no difference between amateur and professional photographers under the law. In both cases it's a photo uploaded to Facebook by someone who owns the copyright on it. When you upload a photo to Facebook you grant them a license to display it when people see your post. They're not Getty, you're not selling your photo to them.
Like I'm not sure where the disconnect it, do you wish Facebook had a monetization scheme like YouTube? Because that's entirely voluntary. For "pirated" content monetization is a voluntary offering that serves as an alternative to issuing a takedown request.
