Fans at WWE events over the last year have developed a reputation of hijacking shows, starting random chants and heckling the stars they don't like. According to PWS on April 5, the WWE sent out a warning that fans at the WWE Hall of Fame ceremony will be ejected without warning if they start chants or cat calls.
The WWE simply asked that fans in attendance show the respect to the WWE superstars and WWE Hall of Fame inductees while they are on stage speaking.
This makes sense. While the "WWE Monday Night Raw" events have always been a place where fan chants and interaction has been suggested since the 90s by Vince McMahon himself, lately the people in charge have been insulting fans for the actions and many fans have started getting ejected for their chants and signs.
Even as far back as the golden age of the WWWF, fans were very vocal at shows concerning wrestlers they didn't like, so this is nothing new. As bad as some of the chants on TV can be at times, at least they aren't throwing trash in the ring like old WCW fans used to do.
However, the WWE Hall of Fame is a different situation. Yes, it is not a real Hall of Fame in a technical sense, and many inductions are for business reasons, such as Carlos Colon getting in this year because the WWE wants to purchase the WWC video library. However, it is still a time to celebrate these wrestler's careers and inappropriate chants at the WWE Hall of Fame ceremony would be inappropriate.