I always give my clients a choice.  They can either phone IRS when they receive a notice, or they can phone me.  If they choose not to call me, I'll just take their name off the client list and notify the first one on the waiting list.  

If they do the right thing and call me, I'll take 15 minutes to prepare and file the Form 12153 request for a Collection Due Process hearing.  Then I will make sure it gets mailed to the proper address before the short deadline.  By the time this works its way up to the top of some Settlement Officer's inbox, the extension will have been found and processed.  And you can still argue other issues, like abatement for reasonable cause if it turns out the dog ate the extension.  

Taxpayers have rights.  Why do people choose not to exercise them?  Maybe they figure for what they are paying the phone company, they have to get the most from the service.