The Rockies have the ability to change the on-air talent if they so choose.  Even if contractually there were to be a problem, the announcers count on the club helping them.  The club can make life uncomfortable for the on-air talent but since these are "homer" announcers, why would they?  I am sure Spilly is there because of his history with the club as much as his talent for game-time commentary.

Nowadays there are few fans that want to hear negative comments about the home team.  The Broncos being an obvious example.