One of the worst sitcoms of the new season stars one of TV's funniest actors, Dabney Coleman. Fingering his moustache with understandable fidgetiness, Coleman plays Otis Drexell, a cynical schemer who's teaching fifth grade until something better comes along. What this means is that Drexell is about a man who has complete contempt for the young minds he's supposed to be molding. But then too, his class is a sullen, sarcastic group that makes the teen dunderheads in Welcome Back, Kotter look like geniuses. There's no one to root for in this series.
When he's not supported by a strong, funny script as he was in the great Buffalo Bill and the more uneven The ''Slap'' Maxwell Story, Coleman's tough-guy act can come off as merely hostile and obnoxious, and that's what happens on Drexell: ''Go play tetherball with that downed power line'' and ''Holy hopping snot!'' are two of his more eloquent lines here. Drexell isn't just insulting; it's depressing. D-