Go read through his posts. He was a pragmatist. I really don't think he considered a significant degree of consolidation to be a systemic problem. He may not of considered it ideal, but he probably (correctly, in my opinion) considered it both inevitable and non-fatal.
I'd characterize him as pragmatic, rather than a pragmatist.
Sure, mining centralization was anticipated, but not inevitable.
It is non-fatal to the extent the BGP solution addresses it, which it does pretty well, but not perfectly.