The Conservatives cannot win the next election unless they can put up a credible leader in the French debates. There is also the fact that in the last election, with a Liberal leader from a Quebec riding, the Conservative party increased its seat count from 5 to 10, with Mad Max at bat, versus zero seats in the Maritime provinces. Bernier's French is a delight and his English is better than Jean Chretien's, according to Max. 

The chances of defeating the Liberals are far better with a credible leader from Quebec with actual  business credentials, versus any of the other candidates, including Scheer who has none. Without the Quebec vote, the Conservatives will lose for sure, particularly against a  Liberal leader from a Quebec riding. This  is why the Conservatives have no alternative, despite the number of contestants.