I'd contrast the Liberal leadership battles with the other parties.
For a while the NDP was really on the ropes. There were genuine battles for the heart of the party. And after taking a few hard losses in the 90s, the party was ready for a referrendum on where they were going. Was it time to follow a "New Labor" style makeover as done by Tony Blair? Or was it time to reinvent the party, perhaps even disband the party with the New Politics Institute? By the time Jack Layton came along, there was a huge battle for the principles and ideas that would guide the NDP. Layton found a balance that would heal the divide, modernizing the party without compromising its principles. But the party hashed out some huge ideological battles. The leadership race was very much about principles, ideas, and values.
Even though the Conservatives are technically a new party, you could probably say the same thing about their first leadership race. This whole party came about because the whole movement split in two through the 90s. By the time they were ready to create a joint party, there were huge battles over whether it would resemble the Reform or the PCs, and all the principles and values that would guide that.
Now take a look at the Liberal leadership battles. The battle between Martin and Chretien wasn't some sort of ideological rift. It was because two different wings of the party were fighting over who got the power and the glory in what seemed to be a permanent majority. Once the permanent majority faltered, Martin surrendered the leadership. As the battles continued, the strategic vote for Dion was the compromise in a war between Rae and Ignatieff. And the coronation of Ignatieff was the final effort to heal that divide. But in the party's internal desire to heal, there was no discussion of what the party was supposed to stand for. Just a hope that if they could just all agree on a leader, they could get back to winning.
The 2011 election could have been an opportunity for the Liberal party to do some soul searching. I wonder if Trudeau hadn't shown up, or if they hadn't spent a year panicked that Rae might abuse his position as interim leader, maybe they could have talked more about their vision for the country. But instead it became another race talking about how the Liberal party could reclaim glory if they just had the right leader, and fixing Canada was just a question of getting Harper out. "Electability" was the only goal. This meant that when Trudeau took the leadership, he had no real vision or principle guiding him. So their approach to beating Harper became a lot like Ignatieff's, stealing Conservative policies hoping the peel off Conservative voters.
Yes, leadership elections are hugely important for political parties. But the leadership battle is always a proxy for something else. In the other parties, the leadership choices represented contrasting ideas. In the Liberal party, it never stopped being about power.