So as not to turn the ball over?
I don't know.
Maybe Goff takes the step forward we were all waiting for. And if so maybe McVay learns something from it. But it sounds to me like they did everything possible to make the game easier for Goff and he just wasn't progressing. I've heard some say he was making rookie-type mistakes. Isaac Bruce said he could tell he lacked confidence. Maybe Bruce is one of those people that see a few plays and make sweeping conclusions about them.
Bottom line is McVay decided to not play the waiting game and saw an opportunity, right or wrong, to improve the team now. A bold move. But the Rams seem to draft pretty well in the later rounds and have one of the youngest teams in the league. So if you're going to make a bold move, its good to take some of the risk out of it.
Hopefully it turns out well for both teams. But I applaud this move, right or wrong. But if it's the wrong move you have to learn something from it and move on.