I don't think anyone has ever claimed (Randy included)
that filtering out long prefixes never hurts performance /to
those long prefixes/. Just that the usage of those long
prefixes is small, the effect is often small, and the NET
effect (i.e. on performance to all prefixes) is often improved,
AND the 'public good' effect, in terms of encouraging
CIDR and discouraging disaggregation has benefits for
the global routing table, for everybody, in terms of
reduction of cost (nice statistical demonstration at
last IETF Ptomaine session - please refer to 'belling
the cat' problem).
Are you going to present statistical data to the contrary?