Personally, I try to keep a "curious" outlook, and to regularly try to disprove my beliefs. To me, one way to do this is to listening closely to criticism from viewpoints and perspectives that are different than mine.
Based on my own experiences, including engaging in very helpful dialog with critics so far, I am not convinced that the same kind of anti-FOSS campaigns that we saw, with ample public evidence, from actors like Microsoft and SCO of the past, would be in the interest of Amazon or its customers. It would be the opposite.
But I think it is right, and it should be expected, to continue to scrutinize Amazon, like any other large organization. I try to judge based on actions and evidence, rather than what-if speculation.