I don't quite understand why anyone would not want "free" press. The only thing I could think of is perhaps 'doing business' from the property might break a 'zoning' law of a sort.
My guess: the owners are uncomfortable with the privacy implications of Justin.TV. After all, everyone that Justin encounters ends up being broadcast live over the Internet. Many other tenants in the YScraper may not want to end up with their mugshot on the net. This also explains why they would evict anyone who regularly comes in contact with Justin: if they're friends with Justin, then Justin is likely to come over and visit, with potentially negative privacy implications for other tenants.
You wouldn't want free press because you have your users that you like, and your business is apartments, and so you don't want any more users, so you don't want any more press. You just want peace and quiet, like you used to have, and a constant revenue stream. Not everybody is looking to take over the world.