Ronacher should also know better than to post microbenchmarks like the one provided here, especially without corresponding (C) profiler output. At the C level, slots allow the implementation constant-time access to the most common code paths for an object, and especially when you have C code calling other C code via the type system (IMHO the primary use for Python, and still its strongest use case), "interpreter overhead" is reduced to a few extra memory indirection operations.
In the alternative world, sure, perhaps some microbenchmark may behave faster, but now systemically, and for e.g. "reduce(operator.add, range(1000))" requires more hash table lookups than I can count.
Python is all about providing a lightweight way to compose bits of fast code (the kernel, network stack, NumPy, MySQL, whatever). Unfortunately somewhere along the way solutions like Django got popular, which are almost the antithesis to this old viewpoint. Ronacher seems to be advocating that we should punish the CPython implementation's traditional strong areas in favour of.. actually, he didn't even describe any vision that was impacted by his complaints. He just seems to want the CPython implementation to suffer.
Perhaps his complaint about new-style __getattribute__ would be better suited as a bug report, it seems the only substantial observation made about the language itself in this post.