The reason given for the rule was primarily player safety. ("save the children") But this past year, Dave Bartoo at his site “The College Football Matrix” provided data showing that slow teams had more injuries in 2012.
The types of teams in favor of the rule are the ones who run slow methodical offenses. One is Alabama which is loaded with talent. If Alabama is able to match up their players with another team's layers, Alabama will always win since they have better players. The other is the 3 yards and a cloud of dust teams (Arkansas under Bielema). The third is the wishbone/ flexbone (Air Force) offenses which are designed to eat up the clock.
One reason I like the option of a faster paced game is that it requires teams to use players who are fast, athletic and in shape. It is more like the days of one platoon football.
Before the trend went to the faster paced offense, a number of teams had gotten to the point where they simply used huge (320+ pound) offensive linemen who were strong, but maybe not very athletic, to push defensive linemen out of the way. (Some teams like Arkansas and Alabama still do.) And the defensive linemen and linebackers had to be large to combat the huge offensive line. It was getting to be more like sumo wrestling.
Bad consequences are sometimes caused by ideas which sound reasonable on the surface. For example, we all know the story about planting Kudzu sounding like a good way to control erosion.
What are the potential bad consequences of doing away with a fast paced offense? It appears to me that the results of doing away with the up tempo offense would be an increase in the number of huge offensive linemen and large defensive lineman who are not very athletic. Would high school players try to get up to 350 pounds so they can play college ball. Is that good? Of course not. They have heart attacks and need knee and hip replacements at an early age.
If the argument of Saban and others is taken to its logical extreme and they are so concerned about injuries (please, save the children ), why not let each team have only 10 snaps a game? And require the teams to take a minute break between each play? That will surely reduce the number of injuries.