No one likes slow play, and you can only play as fast as the rest of the course. All it takes is for a couple of groups a few holes ahead to have a couple of bad holes. People tend to underestimate the number of lousy golfers out there.
There are short hitters who shoot 100 but keep it close to the fairway and aren't looking for the ball all the time. These people play lousy golf but can play fast. There are long hitters who can't keep the ball in play and spend 3 minutes per hole looking for it... maybe once... maybe twice per hole, but they find the ball and have to hit a lousy recovery shot. This group will probably play slow on the greens, too, which will be maddening.