It's possible that Lemmy in general is leftist because the people who came here wanted faster and more effective moderation against hate speech whereas more right wing people didn't have a particularly strong need or desire for moderation.
(...)because the people who came here wanted faster and more effective moderation against hate speech
Interesting, as Lemmy (especially lemmy.ml) was created actually for the opposite reason - less "censorship" (of developers' Communist, "Marxist-Leninist" views). That's how e.g. mod logs came up. And Beehaw (one of Lemmy instances) has complained about lack of moderation instruments.
And the migration from Reddit was unlike that from Twitter. Spez ruined Reddit for anyone, Musk more for left wing and minorities.
Rightwingers more likely to return to current Reddit? I am seeing no clue to this.