I like a good punt return as much as anybody, and I'm baffled why it is such a low priority on our team. However:
Average start position for the offense is the 25 yard line.
Let's say they get one first down and then have to punt.
Average punt is 47 yards.
So that means the returner is fielding on the 18.
Avergar return is 6 yards.
Do you want your returner opening himself up to shots inside the 20 - potentially fumbling - for a gain of 6 yards, or do you want him to field the punt cleanly and trust your offense? I'm guessing that this is McVay's thinking.