No, they don't. It's not entirely settled because the data is new. But no, this isn't true.
There are three variables:
(1) You are somewhere between 3-4times more likely to fumble on a KO return than score.
(2) Kickoffs are, by far, the play that is most likely to result in a concussion. Since implementing the KO rule, concussions dropped from 10.9 per 1000 plays to 2.04 per 1000 plays, so it's a risky play in terms of health/depth of your football team.
(3) Kickoffs are also one of the plays where you are most likely to be penalized.
(2) Since the kickoff rule has been implemented, only about 51% of the returns go beyond the 25 yard line and therefore, but the potential benefit is outweighed by the risk (fumble, penalty (and therefore being inside the 15), concussion, and then the near coinflip of not getting past the 50).
You can disagree with it all you'd like. I think it's a fair debate. I am just saying that it's not a MN thing to avoid returning kicks. It's a drastic trend in all of college football.