For that analogy to hold, PadMapper would have to be pulling data from a large number of sources. The value that Google News provides is that it aggregates a very large number of sources. PadMapper does not.
In my city, Craigslist is hardly used for rental listings. Everybody uses kijiji.com, which is available on Padmapper. There are alternative data sources, and they are actually used. Just not where you are.
It's pretty clear PadMapper was BUILT off of Craigslist that CL's poor UI is isn't entire reason for being, and it never would have been successful without CL. It's disingenuous to ignore that by listing "rent.com" as an alternate source.
But that is where the source of the problem is - CL has the largest user base for listing and classifieds on the internet and since they have the monopoly on this they have never felt the need to improve the experience on their site. Now that padmapper has started getting large number of users CL feels threatened and is suing them to shut them down.