Everything that is about to happen to the party is the direct and foreseeable consequence of choices they made in the years and months leading up to the election.
The Conservatives consciously, strategically, chose to alienate legacy media in favour of pursuing long-form interviews with partisan, niche, or outright conspiratorial outlets and personalities. This gave them great interviews, but these performances never got much reach outside of the converted. The Conservatives struggled to build a coalition outside of their pre-existing base of support. They were not able to persuade the persuadable.
This was a choice.
When the CPC rode high in the polls, they actively alienated, and even picked public fights with, other factions of the Conservative movement. They could get away with this as long as they were winning; but when the polls turned, the grudges lined up, and by the second week of the campaign, long-time Tory strategists were publicly trash-talking their own team.
This was a choice.
Pierre Poilievre is not ideologically aligned with Trump — but he did choose to ape Trump's tone and language in an attempt to siphon off some of Trumpism's momentum at home. With no plan to pivot away from pocketbook issues, this set Poilievre up for a backlash in the event of a Trump victory. A very foreseeable Trump victory.
This was a choice.
The CPC ran a campaign tightly focused on Pierre Poilievre himself. There was little to no attention drawn to other MPs or experts within the party. There was no transition team, nor any detailed policy released to the public until the last days of the campaign, which had the effect of making the CPC seem overly centralized around a polarizing individual, with no credible plan to address systemic and complicated problems.
This was a choice.
The end result was a version of the Conservative party that is more insular, more petty, more immature, and more shallow than the incumbent party they sought to upend.