I often threat to post a sign in the office that says:
Your failure to plan, file, respond, pay, read the form, keep the records or consider the source of information is not My emergency.
The only thing stopping me is concerned that someone might take as a refusal to help them straighten out a tax problem. That is not my intention. My issue are people who get themselves into trouble and expect me to be more concerned about the problem than they have been.