Grammatical gender is not intrinsically sexist and doesn’t really make a lot of sense if you try to analyze it to tease out what patriarchs were thinking when they added these forms, because largely they never thought about it at all. The forms evolved over hundreds of years.
I can't say I follow these things too closely, and I do find them silly, but I think that, at least for languages that have "genders", this mostly comes from words describing professions that "seem gendered". I don't think many people care if a bag is feminine or masculine.
For example, in French, a doctor is "masculine", but a secretary is feminine. The point was that young girls would see these words and figure, "I can't be a doctor because I'm not a man. Guess I'll just be a nurse (which is feminine, but also has a masculine form)".
Now, I think there may be some kind of truth to the fact that many such professions were traditionally held by people of the "same gender". And, now that these traditions don't hold as much anymore, especially for "prestigious" professions, people want to make a point that there's a difference, especially in things like politics and medicine.
Of course, I don't remember much noise being made about how to call a woman who picks up garbage (though there are quite a few) or does construction work (haven't seen that many).
Nachweise erbeten (citations, please). :)