I think because of the assumption by GM's that these genius coaches see something in these guys others don't, and it's assumed they are going to sponge all this knowledge and be the same type of guy...when that rarely happens. Brad Childress is the perfect example. Long time offensive coordinator under Andy Reid...never called the plays. The Wilfs took the bait based on media hype and Childress was a disaster with his "kick ass offense" until Favre showed up, started calling his own plays, and saved Chillys ass. I like O'Connell's upside, but again, never called the plays..so there's risk there in assuming he's just going to magically come in, be Sean McVay, and we are going to have that same type of success. The Rams won the Super Bowl, not because of great coaching, they won because they mortgaged their future in acquiring veteran pro bowl players and went all in. It's why McVay is already throwing out the retirement rumors, because when the time comes to pay that bill...he's gone and won't stick around to tarnish his reputation.