My view is, we need every play we can get. We have to make our own luck this year and give our best athletes every opportunity to make a play. We need six wins, if Ish is our best chance to make a play, he needs to be out there to do it.
Hell by your math, he's only going to return 3-4 punts a game, which means his chances of getting injured are still significantly higher as a WR.
As to the NFL argument, everyone on the roster is fast and elusive. Many guys were top notch PR guys in college and frankly many top #1 WRs don't have the body type to be top return men. Calvin Johnson, Roddy White, Julio Jones, Larry Fitzgerald, Vincent Jackson, Brandon Marshall, A.J. green, I mean these are all big bodied guys not smaller shifty elusive dudes.
At the college level their are only so many elite athletes per team (even on the SEC teams) so the stars do more, simply because they are the best and it isn't even a question.