So in the scenario I painted, to which you responded with the above comments, what makes this hypothetical receiver better is whether his team's kickoff coverage team does its job in the last 3 seconds of the game, and what makes him worse is that his team's kickoff coverage team fails to do its job.
This is the argument you have just made. After having seen it put in these terms, is that what you really believe?
No, you have 60 minutes to make enough plays to win the game. Winning and losing counts, not almost winning and almost losing.
There is no single equation to defining greatness but on a team that has won superbowls I tend to want to measure the players by their contributions to those winning teams. And again, I haven't said that Brown has been the better regular season WR. I am taking a qualitative approach to measure respective players contribution to their team's success.