And which other area are you going to take this time from? The point you are missing is that you must rob peter to pay paul, there is a finite amount of practice time to spend. If we score a TD on a return and give up two because we didn't properly prepare, what have we gained?
You are correct that the 4 teams that I cited have excellent talent, so why do you suppose their special teams are mediocre? Are Saban, Swinney and Meyer just terrible coaches, like Brian Kelly? Or have they decided the time is better spent somewhere else?
Also, since you're a fan of anecdotes, do you remember the 2007 BCS National Championship game? OSU returned the opening kickoff for a TD but ended up losing 41-14. Do you suppose Urban Meyer regretted not spending more time on kickoff coverage in practice?