Experts had advised that a prohibition will not make much difference in terms of the number of casualties. They estimate that on a yearly basis about 2 casualties will occur because of the added risk.
In addition, the enforcement of such a law would be very costly, and nearly impossible.

Earlier this year it had been decided that cyclists will not be forbidden to use a cell phone while cycling - basically on the same grounds.

Similarly, transporting children on bikes is not illegal, and using a helmet is not required.


Lady cycling in Amsterdam, with cell phone
(photo from Amsterdam Bicycles - a humorous and informative picture collection by a mildly shocked American tourist in Amsterdam).