Attempts to get people to focus on the broader issue are, at times, an example of a Silencing tactic.
The situation goes like this:
Feminist: "I think that if we did small act X, that might help in this particular case."
Commenter: "I don't think that will be useful because there's still the broader issue of sexism in the world. We should address that at a cultural level!"
The commenter who proposes to address the "broader issue" seldom has any intention of doing so personally, and is using it as an attempt to shut down discussion of the narrower issue.
The "broader issue" argument is an example of "the best being the enemy of the good", and also fails to recognise that in the absence of top-down, worldwide decrees that sexism will now end, localised improvements and grassroots efforts at a small scale are among our best tools for bringing about cultural change.