The point isn't how the rookies got in the lineup, it's that they are starting and having success. Okay, so the plan wasn't to start each and every one of them but even if their hands were forced, the reality is far less heralded rookies are starting and helping their teams. I don't see why Goff wouldn't be doing the same. Unless he is truly worse than all the other rookies. Let's not forget, Keenum is THE worst starting QB in the league right now by a wide margin.
If Fisher was truly worried about the QB position hurting the team, he'd have made the switch already.