Not really, but I have finally returned

I see Beer has written a book

But I suppose the original topic is relevant on my mind at the moment. I see alot of FOSS zealots chanting this slogan over and over again. What I want to know is; What are you setting us free from? Most of us are not stupid(after seeing that 60% topic im starting to wonder) and know what we get with a big company like MS. But we also know what we would get with something like a Linux distro(heck the only distros worth running are from major companies)
So please, tell this unenlightened fool

What are you setting me free from? What cosmic truth am I missing while not on the FOSS bandwagon!
Preach it to me!