"Linux is quietly running on a myriad of embedded devices"
Sure, outdated version of Linux are running on myriad of embedded devices. And being FOSS doesn't automagically keep them up to date. And it's there only because it's free - there were embeeded OSes before, just how can you compete with "free"?
"FOSS has made the world better, and quite demonstrably so."
Really? In which ways? Making companies pay developers less? Letting Facebook, Google and Amazon amass an enormous power? The world looks worse to me, actually.
"The problem is how corporates use and abuse it."
And do you really believe that giving something away for free could end in a different way? Again - it's just some kind of religious belief sustaining FOSS - and like all religions, it's designed to exploit the most for the benefit of a few...