Because they don't and NEVER will understand customer service. I have had other FCMs call me on my biz line, home number, cell phone, every number to reach me when there is an issue of this nature. And I am NOT some super duper HUGE client with a $100M account. IB just doesn't get it...! Very sad, becuase their approach to transparent/fair priced commissions and multi-asset trading should make them a raging success in this era of electronic traidng - but theywill never reach their full potential!
I kind of agree with CPTrader. The point is that sending out that one e-mail will make life easier for thousands of clients and would probably reduce the number of calls/e-mails to customer service.