There is a very large premium for J/F tickets ex-DXB, so many people buy a ticket to position out to, say, Europe or Asia, and then buy tickets that connect through DXB to another destination they want to go to in the future, but have a very, very long "stopover".

That is a loss of revenue to EK who want J/F pax to buy 2x round trips ex-DXB at the high margin prices rather than a more competitively priced routing that does the same thing.

This is mainly done by J/F travellers only because of the major price differences, so the 30 day rule cracks down on this, without inconveniencing those who have "legitimate" stopovers.

Unfortunately sometimes some people with legitimate reasons such as yourself are caught out by this.