The data certainly exists for computations on contaminated runways - however there is no regulatory requirement to apply any of that data for takeoff. Just imagine the runway requirements for a high speed abort on a contaminated runway in a large transport aircraft....you would need the Bonneville Salt Flats to stop it (remember, no reverser for performance computations).
The ATA and FAA I think are in bed on this topic. It always has amazed me that certain really non-consequential performance calculations are required and carried out to the third decimal point while this GIANT loophole exists.