the veneer was not sliced that thin. once the face veneer is glued to the core, the panel is run through a wide belt sander (a 52" wide abrasive thickness planer). how thick the core is and what the thickness it is sanded to determines how thick the face veneer ends up to be.. I've even seen face veneers so thin you could see the core through it.. this is a matter of quality control and does not mean that all of the material from a supplier is like that. what you ended up with is a defective sheet and they should give you a refund.
I suggest you contact a local cabinet or millwork shop and ask them who their supplier is and get your material from them rather than Home Depot or other places like that. a lot of cabinet shops will sell to you from their own stock too if they have it on hand, some even have presses and can layup custom veneer for you.. it's more $$$ than H-Depot but cheaper that you think and a much better product. also there will be a millwork company in your area that does work for the school board and they buy Birch ply by the lift. they always get good material as cost to school board is not a problem.. they are likely the best place to look for Birch
FACT.. all the sheet goods sold at Home Depots and local lumber yards is the stuff that does not meet quality requirements for professional cabinet and millwork shops. it's the leftovers. #2 quality at best.. I know this because custom millwork is my business..