Steve Young analyzed this perfectly after the last MNF game. The NFL knows they have a perfectly inelastic product and a monopoly on football. People will watch no matter what, and they have propagated this fallacy that having replacement refs does not matter because the regular officials miss calls too.
Keep in mind that the regular officials have not made this process any easier (they are part-time employees and have other jobs to support themselves during this lockout). They are demanding more than it has been made to look like by the media; however, that being said, the NFL is a billion dollar annual industry. And given how obsessed Goodell claims to be with the integrity of the game, you would think he would be looking for a way to compromise, but with the player hold out over renewing the CBA last year, and with his authority being challenged on the whole Vilma/Saints issue, Roger Goodell is taking this opportunity to re-assert his power. This is why the NFL will not budge; they are saying, "We don't need you, you need us, so take what were giving you or GTFO!"