The story Steve linked to explains it in part. NBC has 300,000 square feet of space in its NBC Sports Group headquarters in Stamford (it leases half of the old Clairol plant). Even with NBC Sports, NBCSN, the Olympics unit and offices for regional networks, there's room left over. Put Golf Channel there to fill it and you can sell the Orlando building. Makes sense except for everyone who'll have to move, and worse for those who are left behind.
It's also the way of the world in TV. Your local station may have studios in your city, but master control might be located halfway across the country with a bunch of co-owned stations, where a couple people do the work of dozens. Fiber optics makes it possible.