There's a lot of Zotero code on GitHub, but I can't find Android version there

Expecting(hoping?) software you run on your hardware to be libre shouldn’t be dependent on your abilities to develop and publish software , open source or otherwise.

Not everyone, even in this forum is a software developer, and out of those who are - most work for an organization therefore don’t own what they develop and have limited influence to choose licensing of their work product.

At best we can perhaps maybe point out someone’s hypocrisy if they already develop software who’s licensing is under their control(I.e. not paid for by someone) and is also closed source and at the same time demand for open source from others . Even then I don’t think it is a good sentiment to have .

It's not hypocritical for someone who's never published any software to say that. It'd only be hypocritical for someone who's published non-open-source software to.