Scenery chewing can be a good thing. On stage, consider Norbert Leo Butz in Dirty Rotten Scoundrels. The role called for scenery chewing, and he delivered big time. On screen, Margaret Hamilton chewed every bit of scenery in The Wizard Of Oz, and the result was perfection. Many roles require scene chewing: Miss Hannigan, Adelaide, etc.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson