Enjoy institutions having the freedom to express political opinions, it is not guaranteed to last.
Everything exists within the political climate of modern society. Institutions are forced to navigate the political landscape in which they exist.
But that does not make the institutions political in nature. There is absolutely nothing political about studying the mating patterns of beetles or the composition of rocks.
When people say that SA is being political, they mean that SA is using science to thinly veil their political activism. That's very different from your definition of "political"
Well, what about studying the mating patterns of humans, studying the decisions to abort, studying the decisions to change gender? Still not at all political in your country? Then, who decides if a study gets funding, who decides if it is ethical, who decides if the results can get published? It's all political decisions around the 'pure' science, which is why I mention different political regimes where stuff like this is often completely explicit unlike in more free societies where it may look like it's free of politics.
> they mean that SA is using science to thinly veil their political activism
And they should be glad, not complaining. Everyone is using their position for political activism, business owners, unions, all sorts of organisations, churches etc. There is no reason SA shouldn't do that. Of course they only complain because they don't agree with SA.
Just because scientists have to occasionally interact with political institutions does not make Science itself a political institution. Science is fundamentally apolitical.