If a serious percentage of companies started giving people Friday off (or maybe Monday, which is worse?) at some point everyone would do it since people wouldn't be able to get work done on that day. It could happen.
I work for a defense contractor in Los Angeles and that's exactly what's happened in our industry. I'm not sure which company was first, but nearly all the defense corporations here are on the 9/80 schedule where you work 9 hours/day (80 hours for the 2-week pay period) and get every-other Friday off.