Voters tend to vote against the Party or leader that upsets them the most and vote in the other Party or leader that presents the best prospect of defeating the disliked Party or leader in question.

Kevin O'Leary is embraced by a narrow segment of voters as their man to vanquish Trudeau, the Liberals and all they stand for but O'Leary lacks the personality and skills needed to broaden that segment or lead a government in office.  Thus, if the PM and Liberal Government really enrage the majority of Canadians (little sign of that yet) and Trump and the GOP are a great success in governing (Do we really think that is likely?), then O'Leary might succeed in getting elected but his chances are blindingly slim.

He really would be a disaster as a PM (apart from issues of policies, etc.) because he lacks the capacity to build a team and public consensus; attributes necessary in a leader if a democratic parliamentary form of government is to work.