It doesn't follow the latest web9.0 flat^Wmaterial^Wlook-a-monkey! design trends?
The interface remains usably utilitarian?
They don't try to capitalize to create an uber-exit that everyone can write a congratulatory comment on YC/TechCrunch about? Great hustle Craig!
Or is it just that you're of the Uber-style ethical camp that believes in disruption-through-cost-externalization? In this case, actively extracting value from Craigslist, despite their protests, and using it to undermine their business.