I kinda feel bad for him to tell you the truth. It's something he REALLY wants to do, let him do it. Yeah, he needs to learn to fair catch. But it's obvious he just felt like he needed to come out and prove himself right away, or else the opportunity would be taken from him. So he took every opportunity to run the ball back. Give him a few more returns, and he'll be smarter about his decision to fair catch the ball. He won't feel the need to "prove" himself, just in order to keep the job. We all know he's got the ability to take it to the house on any play.
Fans WERE being selfish. He's the one who is putting his body @ risk, yet we're the ones talking about his body like it should be in our control. But only because we needed him to be able to play @ his elite free safety level. We're so concerned about him getting hurt, but he can get hurt on any play- punt return or safety. It's selfish to be only concerned about the risk of injury, that we forget about his own happiness. It's football, people get hurt all the time. Let him enjoy his job.
Hypothetically speaking, what if it bothered him so much that he didn't want to play for the Seahawks anymore- and instead he wanted to go play somewhere else where he could be the punt returner, because it makes him happy? Would you let him return the ball then? The obvious answer is yes, and if it is, then you're definitely being selfish.
At some point, you have to let the players have fun and enjoy themselves- and that is the cornerstone of the Seahawks, and I think what makes them so good. It's not your body, it's not your life, it's not your decision.