That's true and I'd probably not use the software myself if the dev was someone known for stealing credentials or something, but honestly I don't really see how someone viewing the use of "they" over "he" as political propaganda could affect the browser they're making negatively in a substantial way.
I guess you could say that there is a possibility that he's saying that out of homophobia and when ladybird becomes as influential as google they could do some homophobic things? I really doubt that'd be allowed by governments though