The thing is, Craigslist's model is not out to screw people. Craiglist is in no way an abusive monopoly. It's exactly the opposite. It is abusing monopolies, murdering monopolies, sending monopolies to their graves, almost literally. It's million dollar site that has destroyed multi-billion dollar industries.

Yes, craigslist makes it hard to create a craigslist mashup. But craigslist exactly as it is, no modification, is accessible to nearly everyone for nothing and to everyone for nearly nothing. It makes perfect sense to guard that situation jealously.