While the reaction may be a bit outsized, it the OP's luggage was actually tagged to DXB at check-in and later, at the gate, was "retagged" transit to DOH.
Yup, this is the strange part. Never heard of this happening. Though less severe it is similar to the board a plane then get asked to deplane scenario in that you were given something and then it was taken away.
When it comes to people's expectations of what is fair, it doesn't matter what the rules are. It matters that you actually put something in their hands, then take it away. Most people will find that unfair.
I'll agree that this is an overreaction. However, if it was handled at the check in desk I think the situation would have been a lot more straight forward.