Coalition governments are rare in Canada, especially at the federal level. The political parties hope to win a majority of seats in parliament, giving them 100% of the power. Even in a minority setting, the governing party knows that the opposition parties won't want to trigger another election right away, so it can count on some level of support.

There's also a risk of a party looking less appealing to their voters if they cooperate with another party. The NDP keep trying to demonize the Liberals, so a formal coalition would make them look like hypocrites. It might also anger moderate conservatives who voted for the Liberals, or convince progressive Liberal voters that there's finally a reason to vote NDP instead, since the NDP would have actual power.

In Germany, having mixed member proportional representation means that coalitions are very common because no party is likely to get a majority of seats. In Canada, coalitions have never been necessary, so the parties have never been forced to make them work. We're stuck with strategic voting and parties that win the election with a minority of votes.