Clearly people are still finding value on CL. Hacker News readers are in a demographic that views the internet and the web VERY differently from how people who do not create internet services for a living view them. We care about a completely other set of factors then they do.

We don't bookmark facebook.com we rely on the browser history, having typed it in to the address bar once. They use google to search for the link to the facebook login.

They hear that CL is the biggest site for classified ads, so they post there. They don't care that padmapper will put their apartment on a map, they don't care about other sites.

CL did the hard work of attracting the people to the marketplace. Padmapper is not doing any of that hard work. It is my opinion, if you're doing the hard work of building the community and attracting the users, then you'll agree with CL on this issue. If you're a repackager, then you'll side with padmapper.

If your business idea is "Some corner of Craigs List with a better UI" then by all means, build the UI and then convince people to GIVE you their data.