1990 World Cup: It really was the era of defense
For someone like myself, who didn't get into soccer until MLS started, you always hear about how the game was much more defensive. The 1990 World Cup is famous for being the most defensive of all time, with only 2.21 goals per game (GPG). Since then, FIFA stopped allowing goalkeepers to pick up back passes, and along with other rule changes the scoring has picked back up. But I think we should look back and see just how bad it was. Here are the GPG of the last continental tournaments before that World Cup:
2.12-Copa America 1989
1.67-Asian Cup 1988
1.44-African Nations Cup 1988
It was clearly an epidemic. I can't even imagine a tournament with only 1.44 GPG (Out of 16 games, in only 2 did a team score more than once). So it was pretty bad. Since 1992, only the 2002 Gold Cup (1.95), the 2001 Confederations Cup (1.94), and the 2002 ANC (1.50) were under 2.00.
I figured out the GPG for every confederation championship, including the older Oceania and CONCACAF tournaments, and I also included the World Cup and Confederations Cup. So here's the data for 134 tournaments: