I think you are correct, but also there is another factor:

Canada, as a polity and an electorate, is a country that leans a bit to the left of centre but not overwhelmingly so. If I were to guess, Canada as a whole is an an electorate that's maybe 55% left of centre, 45% right of centre.

Of course, these are big categories and that 55% left of centre includes everyone from centrist pro-business Liberals to democratic socialist NDPers to left environmentalist Greens and everything else. Practically speaking, it's exceptionally difficult to keep all the factions of the Canadian left of centre unified behind one party and one direction. There are deep fissures within the Canadian left as much as there are on the right.

As a result of that, plus various other things to do with our constitution and electoral system, governing Canada often requires at least a bit of support from the other side of the ideological aisle. A conservative government often needs at least a bit of support from otherwise left-leaning voters and their representatives. A liberal government, contrarily, will also often need at least some support from otherwise right-leaning people. Canada cannot be governed otherwise.

This is really critical. Canada cannot be governed, the crises that press upon us cannot be met, solely on the electoral strength of all the nicest, most liberal, most progressive, most left-leaning Canadian people. There aren't enough of us! We actually do need support from across the aisle. We don't have to like it, but it is the reality.

I don't like Marilyn Gladu anymore than any other left-liberal does. I wouldn't vote for her, if I lived in her riding. But if she's willing to vote with Carney and work together on the national interest, well, Churchill once said "If Hitler invaded Hell, I would make at least a favourable reference to the Devil in the House of Commons". If she's willing to make common cause and pull together in the common interest of Canada with the Carney Liberals, well, so much the better then. I too would rather have Marilyn Gladu as a Liberal backbencher voting for Liberal measures . And it is to be hoped that Marilyn Gladu's odious beliefs can be held in check by her membership within the Liberal Party caucus.

We can also take some solace in this: Voters usually condemn the aisle crosser. If the conservative voters of Marilyn Gladu's riding dislike this choice, as I suspect they will, they can pass judgment on it at the next election.