I assume you're talking about PMs but imagine if 100s of users have the same question and bombarding the user's inbox it will be more annoying and replying everyone in personal is time consuming right. 
That would already be the responsibility of the user.
If he gets so many requests, he might find it productive to create a topic, or choose to respond.
In turn, if the other users did not get a response, then yes, they could expose the situation, indicating that they tried to get a direct response from the person involved.