(Author here)

To be clear, in real life, I do not actually like Subversion. I use Mercurial pretty exclusively for my own stuff, and would indeed use some of the centralized Mercurial extensions I linked in the article (e.g., remotefilelog, narrowhg, etc.) to scale upward if I had really big stuff flying around. The article is more about pointing out that going to a DVCS involves trade-offs, acknowledging that we have a lot of tooling designed to fake out those trade-offs, and discourage thinking of DVCS as a strict upgrade rather than an engineering decision with implications and costs and benefits.