The decision by PBS to fire actor Fred Willard after his arrest for lewd conduct at an adult movie theater in LA is spurring something of a backlash. The network wasted no time in canning Willard, who was narrator of the WGBH-produced show “Market Warriors,” a spinoff of “Antiques Roadshow.” (In a statement Thursday, WGBH flack Jeanne Hopkins cited “the unfortunate news” of Willard’s arrest as the reason for his immediate dismissal.) That decision didn’t sit well with a lot of people, some of whom tweeted #FreeFred and “Shame on you, PBS.” Writing in Entertainment Weekly, Ken Tucker also criticized PBS. “How does Willard’s innocent-until-proven-guilty status merit this? Will viewers really refuse to watch ‘Market Warriors’ because they’ll be repulsed, outraged, by the sound of Fred Willard’s voice?” Contacted Friday, Hopkins said she had nothing to add.