In Trottier's defense he was competing against Gretzky for awards throughout much of his prime. In '82 for example he finished 2nd in Hart voting behind 99.
That's kind of my point though. Orr and Gretzky were both extremely tough competition, and Orr was arguably a better player than Gretz at his best. It shouldn't be held against Trottier for not beating Gretzky, but the fact Clarke beat Orr is huge. Though, Orr being a defenseman may have made him less of a threat given how voting has gone historically.