Earlier quoted context omitted.
I am well aware of the foundations of CS and the lambda calculus, but this is more than a bit reductionist, like saying "everything is made of subatomic particles." Patents on processes and methods are pretty common. Dismissing it as "they just patented some math" and then falling back to saying "oh, lambda calculus" -- I think you can do better :-) But, yes, I'm sure the patents suck.
Why should Free software advocates need to "do better" than to argue from literal first principles? Fourier could call his transform a "process" all he wants, but that does not make it patentable. So yes, "oh, math."
I'm not in favour of patents at all, but the entire "it's math" argument has always seemed exceedingly weak to me.