If you use lemmy.ml (the developer's instance), I would recommend reading the front page sidebar. Under RULE #1 - "No bigotry - including racism, sexism, ableism, homophobia, transphobia, or xenophobia".
Here is a screenshot for reference, feel free to share with folks.
If the enemies of Nazis are religious, ethnic and sexual minorities - then lemmy.ml 's front page immediately puts to rest any notion they are associated with far-right ideologies.
That said, my best understanding is that one or more of the developers identify as communists/anticapitalist and are involved in lemmygrad.ml and /c/socialism.
And with that in mind, a platform like Lemmy is communist by nature: nobody owns it.
So it doesn't matter who the developers are, really. What matter is who runs the server and instance you're using. You, as a user, have a choice in how you wish to connect to the Federation.