I think you missed the point. He's not denying that make is slow and could be faster or that most of it doesn't have to do with page-faults. All he's saying is

I think you missed the point. He's not denying that make is slow and could be faster or that most of it doesn't have to do with page-faults. All he's saying is that page-faults in general are slower and speeding them up would improve lots of various different kinds of loads besides just the kernel build system (Which would probably not improve very much from just that alone). I'm sure he'd be happy to take patches that make 'make' faster, but that's simply not what he's trying to address here.